Pure basics are:
1. Pawn in the center
2. Develop your pieces
3. Get your king safe (this doesn't necessarily mean casting!)
4. Connect your rooks
(5. Rooks on open files)
Combine that with some tactical knowledge and you're fine.
I would mainly study openings to know a few concrete things (tricks and traps) and general ideas. It's not very necessary to memorize specific moves and variations too much.
1. Pawn in the center
2. Develop your pieces
3. Get your king safe (this doesn't necessarily mean casting!)
4. Connect your rooks
(5. Rooks on open files)
Combine that with some tactical knowledge and you're fine.
I would mainly study openings to know a few concrete things (tricks and traps) and general ideas. It's not very necessary to memorize specific moves and variations too much.