As a beginner should I try different openings or stick to Ruy Lopez and the Italian game?

At the moment I exclusively play these as white. 

Then what do you do if black plays the French or some other defense? . . .

Try to make objective moves... whichever opening..... your decision.... if you want to change or try new openings....... openings depend on you playing style as well....

Yes, stick to the few you know. It might seem boring but it helps you stay consistent when still learning the game. My advice re openings for beginners. Stick to one opening, E4 or D4 and if you come across an opening reply you've never seen before, try to develop naturally.

In my case, I have only reviewed two openings as white (Ruy Lopez and Open Sicilian) - dependent on if the opponent responds E5 or C5.
For black, I have learnt one opening re D4 and if E4 I exclusively play the Sicilian. 

I wouldn't spend too much time learning lots of openings. Stick to a few you know and spend the rest of your time on tactics and endgames. The latter two are the most important and decide the majority of the games at the beginner-intermediate level.

It depends on a few different factors including, but not limited to:

-Your confidence is trying out openings and positions you are unfamiliar with

-Willingness to study a little chess. Perhaps not full out opening theory study of lines and variations, but it is at least a good idea to know a few basic themes for various openings.

-Chess play-style and personality

I would recommend focusing on "opening principles" and "plans" of your own as well as the opponent. By "opening principles" I am talking about a set of established guidelines for the opening stage of a chess game where you can typically get a solid position with little to no opening theory memorized. Some of these guidelines include: developing pieces (not pawns), castle early, control the center (specifically the squares e4, d4, e5, d5). Following opening principles also has the added benefit that you should never be 100% confused about an opening the opponent plays against you. At worst, you can just develop pieces and such and get a decent position.

I think learning (and especially experimenting: even if only unrated games) many openings is a good thing. Not only will you become better rounded, but you'll be more adaptable and tougher for an opponent to study against. You will also learn which openings you like more (even if through lots of trial and error) and discover what positions you are better with. 

I would pick a "mainline" opening that interests you (Good choices are openings like: Italian Game, Ruy Lopez, Scotch Game, Queen's Gambit, London System etc. although for the London System, it isn't good is you are playing "system" moves in auto-pilot without thinking for yourself). Another idea I've heard is also experimenting with fairly solid openings that are not necessarily best, but may give you an advantage if you know a little theory (usually tactical openings though). Openings like the Scotch Gambit, Benko Gambit, or even the Wayward Queen Attack come to mind; they are a bit more "off-beat" (and debatable if solid or not) but they will teach you certain themes like keeping the initiative or the importance of piece development. 

I recommend you start playing other openings too. Start to learn them all. Learn a little of every opening till you get the picture then you can choose what one you like best & then practice using them ones more. One day I will be able to play any opening I choose so my life wont be getting boring till I'm dead

First of all, I have to ask: What are your goals?  To improve your game a little?  To become a good club player?  To compete in tournaments?  There are different approaches for different goals, so knowing what you want to do is a starting point to improving.

Another question is what type of game do you prefer?  Do you like imbalanced, tricky positions where surprise moves rule, or do you like patiently playing for advantage and/or the endgame?  Opposite side castling or trading queens?  This is another question you need to answer for yourself.

If your rating here is an honest approximation of your actual abilities, and you like e4 as a first move, then I would suggest the Scotch as a good place to start.  There's a lot less theory than with the RL or the GP, your development problems are easier to overcome, and some lines will transpose into GP lines.  At club levels this is a good line, and once you get the basic idea of the basics of the opening, then you can progress to more challenging lines like the RL.  But you have to get the basics under control before you try to involved with the more advanced stuff.

Another thing to remember--the lower the rating, the less important the opening is.  When I was a beginner I used this set-up for my first 4 moves: 1.Nf3, 2.g3, 3.Bg2, 4. 0-0.  I'm castled, have a solid kingside, and a B at g2 that defends the king while eyeballing e4, d5, c6, b7, and a8.  After the 4th move, I'd start playing chess and try to respond to what black was doing.  But for my first two years of playing, that was my opening.

It's not a bad idea to take a look at all the major lines, but only a brief look.  There may be a line or two that interests you and may inspire you, but most will confuse you and leave you lost.  Don't sweat that, that's only your limited understanding of the opening showing.  I'm a USCF Expert and there are a lot of lines I've seen that I wouldn't dare play even now because I just don't see what the point of the play is.  Needless to say, they are not in my repertoire.  Just because Magnus uses it doesn't mean you have to or can.

If you are going for tournament play you will need to know your white opening and black defenses in a bit of depth, and the higher you go the more critical it is to know what you play.  Being familiar with a wide variety of lines helps a lot, as you might find (as I often do) someone playing a weak line that you can take advantage of that isn't your usual stuff.  It doesn't mean to try to memorize the ECO but if you know who your opponents are and know what lines they play you might be able to set up an ambush situation by doing your homework.  But that comes later.

The way I studied (and to some extent still do) is to play over full games of players whose style I liked.  I read Morphy, Alekhine, Tal, Fischer, and when  didn't understand what they were playing in the opening, that's when I would hit the opening books to learn it.  If what I was looking for wasn't in them, then I'd ask other players if they knew.  If that didn't help, I wouldn't lose sleep over it, I would just enjoy the game and accept the fact that I wasn't strong enough to understand it, and so I wouldn't play it.  Beating ones head against the wall isn't pleasant and it feels great when you stop.  But now you can post questions here--this wasn't available 50 years ago when I started and it's a great resource to have.  Use it wisely and it will serve you well.

Hope this helps. 

I wish I had learned the Ruy when I was younger. I picked up on Bc4 and have been playing it for ages though I really don't have time to learn what I see as an obviously better opening. 

This is complete nonsense. The " lends you to fear" part is obvious nonsense, but also: no one is going to master an opening by playing against beginners.

At the beginner level, openings are not important at all. Opening principles are important: fight for the center, develop your pieces and castle. That is all.

You will first have to worry about openings when you reach a rating of 2000.

Chess Openings Resources for Beginners and Beyond...

https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond

Make your mind up and play one or the other. Are you Spanish or Italian? How can you play both?

Either opening is fine. Play whatever is interesting to you (hopefully an opening more than 1 GM has played more than 1 time each in a serious tournament game).

But yeah, starting with the Spanish and / or Italian is good.

a very complex opening is the giucio pianissimo

easy to learn

If you're a beginner, I wouldn't accept or attempt gambits.

Nonsense again. No sane GM would ever say that. Everything you say is terrible advice, please stop.

@super-trouper.   I may not agree with the exact wording but I do agree with the points cerebov  is making.   Your statements are not accurate and although the manner is which cerebov is pointing this out may not be pleasing he/she is in general very much correct in his/her assessment of your advice.

I don't have a specific goal yet, other than to improve as much as possible as a chess player. Perhaps being able to compete in amateur tournaments would be the long-term goal.

So far all I have noticed is that I tend to prefer open positions rather than closed ones.

Stick to what you have

I think you should work with different openings likes the Queens Pawn Opening and stuff. For example, if you are playing black, your opponent might play the Queens Pawn Opening and since you have not been prepared for this, you will probably lose. You don't just want to hope that your opponent will play something like 1. e4, right?