Learn a Ruy Lopez as black. Not the Schliemann (spelling?) since you'd need a good deal of skill. Also find lines against the Piano, Scotch, King's Gambit (2...d5! for starters), Four Knights, Danish Gambit (5...Bb4+ and call it a day), Bird (1...d5 or 1...e5 depending on your taste) 1.d4 (Nimzo and Bogo Indian complex may be good but 1...e5? doesn't work here like 1.f4 because black doesn't have a weak king to work against and instantly kills off a center pawn. At best black enters a king pawn esque position where white is significantly better and black can't castle for some time)
Also against 1.Nc3 go for a Caro-Kahnesque position where your c-pawn isn't committed yet:
I have been playing chess actively for about 3 months now and I would really like to extend my knoweldge of openings. I only know 2 openings but I have got an idea about how to play the opening if someone does something I have not anticipated. The two openings that I know how to play are the queens gambit and the sicilian defense. I know it is a really meager arsenal but my question is: what openings should I go about learning? Please just give me a few that I should learn. Im not sure about what my style of play is but I think I play rather passively until I know I can gain an advantage by either aggressive or defensive play. Thanks!