The thing is, in the early going you are ok just playing a basic basic strategy:
1. Develop you pieces
3. play to control the center
4. snap up any material available
5. attack the enemy king
You don't need an in depth opening repitoire (don't repeat mistakes). Just know enough tactics to grab any material available, and not to drop any of your own. At 1200, study endgames as well until you win the won games and fight as best possible in the lost ones. Around 1400, start looking at pawn structures, good vrs. bad bishop and how your middlegame translates into an endgame (won/lost). Around 1800 you probably have your tactics down and you can move into further middlegame strategy, also start studying openings more thoughly.
Thats my theory. Mind you I am only 1500 but I don't study openings much. I may if I'm in the mood play 10 moves out of a book just to achieve a reasonable position, but usually I just play things other people played against me which I liked.