Best to 'master' one opening or learn more?

I've played League of Legends for a few years, and if you are familiar with the game (which has many characters to choose from), the prevailing advice is to main one character and continuously improve the other aspects of your gaming.

Is this advice applicable to chess?  I've been opening every chess game as white with Queen's Gambit and French Defense as black.  I have A LOT to improve on being 1000 rated, so I figured a good way to understand the various lines that come from these openings was to only play those openings.  In the meantime I can work on my middle- and endgame tactics.

TLDR; should I bother adding another opening or two to my repertoire for each color?

Play e4-e5 till you reach 1400. Learn various traps and tactical motifs in e4-e5, then you can branch out to other openings.

I'd say: 2 as white and 2 as black.

That's what opening repertoires are for. For now, play symmetrical openings since they usually provide easier to play positions. On other openings where you can't play symmetrically, just follow basic opening principles and you'll be fine. In those levels, focus on middlegame play. When you become 1400-1600, start memorizing 5-10 moves against common openings such as the French,Caro-Kann,Sicilian etc.

Thanks for the help guys.  How long did it take you all to reach 14-1600 ratings?  I've been playing 5-10 games a day for about 2 weeks and watching a lot of videos online about fundamentals and different openings, traps, etc.

I'm definitely recognizing many more patterns and good responses to certain moves, but it's admittedly a little demoralizing to be stuck within the same ~50 point range after having played about 100 games or so.

Is playing 15-20 min games really all that different from 10 minute games?  It may be due to the low skill of myself and my opponents, but I feel like with 10 minutes, I have adequate time to think about my moves and their followup 1-3 moves.

Rarely due my games time out, and the ones that do are pretty much decided and one person is just stalling as long as they can.

@antinetwork lies. I started a chesscom account 5 months ago(not this one) and was struggling at 900 blitz. I trained my ass off and have gained 480 blitz rating in those 5 months playing almost exclusively blitz.

Sounds good.  The shorter games are appealing because you're in and out, but I'll give the longer ones a try

i use london as white and its good for anyone below 1500 you should try it

I only have four openings that I try to learn: two as White, and two as Black.

When I play as White, I start with 1. e4, and the most common responses seem to be 1. ... e5 or 1. ... c5. So I have a plan for those two.

When I play as Black, I have a plan against White’s 1. e4 or 1. d4. 

That’s it for my opening study.

I have 694200 openings to play as both black and white.

Its really about preference tbh, But if you play a different opening each time, You will understand how to play against it!
"Become the enemy in order to defeat the enemy."

The conventional wisdom is to play just a few openings but I feel the idea of playing a lot of different openings also has the right to exist. I used to play just a few openings, but since I started writing my blog I decided to change my approach for a couple of reasons. First I didn't want to be easy to prepare for and second my blog may be more interesting if I play a wider range of openings. The criticism of this approach is that you won't know the theory that ,deep which is probably true, but in practice I'm finding that for the most part my opponents don't know the theory that deep either. I will say, though, you do need to know some theory......general ideas are typically enough. It takes some time to even learn the general ideas though, so you have to consider if you want to or have time to invest in studying openings. I think if you play a lot or if you don't have much time to study it may be better to play a more narrow range of opening. Playing a wider range works for me, in part, because I don't play all that much. When I play OTB it usually isn't more than once a month and when I play online it is mostly league games in the 45+45 teamleague on FICS which is 1 game per week.

What to do depends on where you want to go. At rating level 1000 few people will know more than 4 or 5 moves of any opening. If you know 5 moves and have an idea the general goals after than you can play the opening, have fun and do well. The key of course is not to memorize more moves but learn the ideas in the resulting MG positions. (If you really want to study openings deeply--you should do it but then focus on a few.)

At some point, especially as black, you will be playing people who know a lot and it will help to narrow your openings, esp. as black, to 1 or 2 vs e4 and 1 or 2 vs d4 and c4. Many find that point starts to happen around USCF OTB rating around 2000.

But, of course, you should do what you enjoy and ignore advice like this if it isnt fun for you. - Bill

You've put in some time focusing on 1. d4 as White. Personally, I believe starting out with 1. e4 to be more beneficial. King's Pawn games tend to be more tactical, while Queen's Pawn games tend to lead to more subtle positional ideas. (Note the use of "tend", there are no universals in chess! )

Anyway, 1. e4 will often, particularly as one is learning, lead to open games, where the centre pawns tend to fall, and you have to get developed quickly and then try to grab some sort of advantage, like controlling the open file(s) with rooks, and so forth. You look for good combinations (tactics).

On the other hand, you are likely to face a number of different defenses by black, with the two most common being
1. e4 e5 (a double King's Pawn game)

or

1. e4 c5 (a sicilian)

After that you may get the French:

1. e4 e6

the CaroKan

1. e4 c5

or the Scandinavian

1. e4 d4

Your own experience will tell you what you are facing most often, so as you play more games, you will want to focus your study accordingly.

Personally, I think starting with the Italian is a very good and principled way to deal with a double king's pawn response.
1. e4 e5 2. Nf3 Nc6 3. Bc4 ...
and you either get an Italian (3. ... Bc5) or a 2 Knights (3. ... Nf6), and you go from there. There are a lot of options for you after 3. ... Bc5, so you pick one line that you like for now. You can later expand for variety. Same for 3. ... Nf6, find a line you like (maybe you hope for a Fried Liver and go 4. Ng5, but you need to know what to do if Black knows how to avoid it (as in 4. ... d5 5. ed Na5 , which avoids the Fried Liver, as it starts after 5. ... Nxd5?, so the Fried Liver is really a line based upon a mistake by Black).
You could simplify things, though, and concentrate on the Scotch Game (1. e4 e5 2. Nf3 Nc6 3. d4 ed 4. Nxd4 ...) and later add the Scotch Gambit (4. Bc4 ...), but those produce very different positions. I recommend the Italian as you can later expand to include the Scotch Gambit as one of your own deviations, and you're building upon the idea of attacking the weak f7 pawn from the get go). You can also eventually add Evan's Gambit, and so forth. One thing is, if you meet Petrov's frequently (1. e4 e5 2. Nf3 Nf6), you will want to look at that too, but again, unless you're facing it frequently, you probably only need to learn a couple moves and you can concentrate on a main line (something like 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 ...).
Find one a line against the Sicilian, French, and CaroKan that you can steer the game towards. Not easy with the Sicilian, but check out the various options White has on move 2 and see which ones have fewer branches for Black. Against the French and CaroKan, you could go with the Advance variations for now. And just take the Pawn in the Scandinavian, and chase the Queen while developing.
The idea is to both minimize the number of lines you need to worry about so that you're reaching similar positions in as many games as you can. As you improve, and face better and better opponents, you will learn the lines more deeply, but really, while you're starting out, your opponent is going to go "off book" long before you get to move 8 type thing, so you don't need to have memorized all these lines deeply. Your experience will tell you which ones you need to learn.
As Black, you can either find something of your choosing (like the French, as you've done), or just play the Black side of the lines you're learning as white (but you may want to look at the Black side of the Ruy Lopez if you go into 1. e4 e5 2. Nf3 Nc6 3. Bb5 ... as Black). While the Ruy is very theory heavy at the top levels, it is a very good opening to eventually look into.
And as Black, against 1. d4 ...,, again, just find a line that you are comfortable with for the Queen's Gambit and the London (the latter you probably face a lot, so be prepared for it).
I believe keeping your Black repertoire small, while having a wider variety of openings as White that are built around a common theme, the most solid way to improve. Remember, as you learn the "White side" of an opening, you should also be learning the Black side, so in effect, while you initially play a limited number of defenses as Black, you should also be looking at the Black side of your games with White. By doing so, you will be preparing for the day when you decide to expand your Black set of responses.
Anyway, that's a long response, where really all I'm suggesting is to consider playing the Italian as White with the idea of expanding that to other roughly similar e4 e5 set ups (ones where your Knight is on f3 and your Bishop goes to c4 ), and pending on how often you face them, find lines you can guide the game towards for something other than 1. e4 e5. As Black, find an opening you can get to most times against both e4 and d4. As you become more comfortable with your chosen lines, start adding options that you can make to mix it up. For example, a while back I started looking into the King's Bishop Gambit (1. e4 e5 2. f4 ef 3. Bc4 ...), because again, the Bishop on c4 is where I'm used to the Bishop being. The resulting games, of course, are nothing like an Italian, but they are a lot of fun, providing you are prepared to lose in spectacular ways just to have the chance of winning in equally spectacular ways!
That all aside, if you are enjoying playing 1. d4, then stick with it of course, because in the end, if you don't enjoy the game, why would you spend time learning about it?

NAWWWWWWWWWW NO WAY THE CARO KANN IS 1. E4 C5???????????

Ooops! Well spotted, that's my mistake and it should read 1. e4 c6

NAWWWWWWWWW NO WAY THE SCANDINAVIAN IS 1. E4 D4????? WHITE PUTS TWO PAWNS IN THE CENTER NAWWWWWWWWWW

Oh dear, I seem to have made a number of embarrassing typos. Indeed, Scandinavian is 1. e4 d5
I rather suspect there will be more.