Do lots of puzzles. This will help improve your board vision, and they are really fun.
Read lots of chess books. If you are a beginner, I suggest Chess for Kids by Michael Basman (IM). This covers some simple tactics, such as Maximum Power, Minimum Exposure. It also introduces chess notation, and it also has a brief history of chess as well.
PLAY LOTS OF CHESS GAMES! Play as much as you can; any type of game improves your skill, especially against opponents a little bit stronger than yourself.
Analyze your games. If you use Chess.com, Lichess, CohenChessClub, all of these you can analyze your games and see all of your mistakes. This really lets you see in areas you need to improve.
