Best to 'master' one opening or learn more?

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?

Actually i agree. The ruy is a opening ever.

Yes, the Ruy Lopez is a very good opening, and one that still gets played at the top levels. So at some point one needs to look into it, at least from the Black perspective. However, when one is not GM level, but just starting, the idea is to work out a good starting point with regards to openings. My suggestions above are aimed at that, a starting point, as eventually one has to get familiar with all of them to some degree, and also to be familiar with multiple different lines and variations. But that comes after you've built a foundation, which will work at the under 1500 level for sure.

By focusing on learning a few lines, to deal with the most common openings one meets, that gives more time to study proper end-game techniques, middle game combinations/tactics, and learn a few positional ideas (if you trade your Bishop for their Knight, where should your pawns go? Where are the good squares for my Knights and how do I get them there? and so forth). It's not really positional or tactical play, but rather it's ideas and opportunities - positional chess reflects underlying good ideas (good pawn structures, control of open files, etc) which will often lead to opportunities, or combinational tactics.

Too much opening study early on can be wasted time as your opponent won't follow the book, but every move requires a decision, and knowing when trading down leads to a better endgame for you is important, and knowing what moves improve your position, and so are likely to bear fruit in the form of a tactic, is also important. Those don't require your opponent follow your book line and so will pay off regardless.

The ruy lopez works because no one knows theory. You 1000s play right into our hands by not studying it.

Well, that applies to any opening one player is familiar with and the other doesn't know. The thing is, though, at the lower levels one doesn't face the Ruy Lopez all that often. So, if you've put the time in to study and learn it, you will generally have an advantage. But from the other side, most players won't face it often below 1000 so at that level one can spend a lot of time learning lines as Black that one never gets to play. As one moves up in Elo, though, one will start to face the Ruy more often, and that's the time to start looking into it. And, by that point, probably start playing it as well as it is a very good opening to learn.
Of course, rather than build around the Italian, one could focus on the Ruy Lopez as White, and then focus on learning how to deal with all of Black's options for defence. I personally prefer the Italian, and find that one can expand into other openings by choosing which opening to go into and making Black respond to White, rather than playing the White pieces and having to learn different lines that Black gets to decide, resulting in White reacting to Black's choice.

Again, I'm just talking about starting out and what to start as one's foundation. Eventually it is good to become familiar with all the openings, but you can't learn them all at once, so focus on a few, and when you feel you've got those down, add something in.

Well, that applies to any opening one player is familiar with and the other doesn't know. The thing is, though, at the lower levels one doesn't face the Ruy Lopez all that often. So, if you've put the time in to study and learn it, you will generally have an advantage. But from the other side, most players won't face it often below 1000 so at that level one can spend a lot of time learning lines as Black that one never gets to play. As one moves up in Elo, though, one will start to face the Ruy more often, and that's the time to start looking into it. And, by that point, probably start playing it as well as it is a very good opening to learn.
Of course, rather than build around the Italian, one could focus on the Ruy Lopez as White, and then focus on learning how to deal with all of Black's options for defence. I personally prefer the Italian, and find that one can expand into other openings by choosing which opening to go into and making Black respond to White, rather than playing the White pieces and having to learn different lines that Black gets to decide, resulting in White reacting to Black's choice.

Again, I'm just talking about starting out and what to start as one's foundation. Eventually it is good to become familiar with all the openings, but you can't learn them all at once, so focus on a few, and when you feel you've got those down, add something in.

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