[amcoastal]

I would second the other reply. While it might seem natural to get good at Chess in a chronological way (early, mid, end), its actually the opposite you want to do. You need to know where you want to go (what endgames are good for you) before how to get there. As far as openings, Id learn 1-2 openings for white (Ruy Lopez and Jobava London for me), and then two openings for black (one for e4 and d4). Id learn the first 15 moves or so and all their variations in case your opponent makes a mistake. Youll win a lot of games that way and then just play conservatively until you are near the end and up a piece.