Play a lot, analyze your games, and primarily study tactics. Your knowledge of openings, endgame, middlegame, etc. will come from analyzing your games and going over grandmaster games. Only study one of those specific topics if it is clear you are specifically losing because of that topic.
Source: https://www.gautamnarula.com/how-to-get-good-at-chess-fast/
As a coach, I can help you with any part of that process. Good luck! 
I am a fellow beginner at 500 rated who is learning chess as well. I have been playing for a while, but have just started to get more serious about the game. My advice to you is to do puzzles, lessons, face bots, analyse your games and improve from your mistakes and face real people.