how to be good at chess

Play slow games, so that you have time to think. Rapid with increment, instead of Blitz.

You can play Blitz and Bullet after you skill-up a little and get used to the patterns.

Don't waste too much of your time studying openings. At low and middle skill levels, players typically study openings as a short-cut, not as an aid to thinking but as a way to AVOID thinking. There is no royal road to chess skill. You'll need to work at it, just like the rest of us.

Your only important task in the opening is to reach a middle-game position in which you feel comfortable and confident. That's it. Everything else is fashion. Chess players are as fashion-conscious as teenage girls.

Instead of studying openings, study end-games - King-and-Pawn or Rook-and-Pawn endgames make up the majority of the endings that you'll face.

Study tactics - pin, fork, skewer, overload, line opening / line cutting, interference, decoying and diverting, etc. These patterns come up very commonly.

Study model mates such as the Smothered mate, the Corridor mate, Lolli mates, Greco mates, Morphy mates, Epaulette mates, Boden's mate, etc. More common patterns worth studying.

Study common Pawn formations in the center - Rams, Levers, Chains, Phalanxes, Jump formations - and the influence that these common patterns have on the middle-game play that follows.

Look over all of your lost games. It's unpleasant, but they are a gold mine of information on which aspects of your play require improvement. Make an attempt to understand WHY you lost each game. Not just "I blundered my Queen" but WHY did you blunder your Queen?

Moving too fast and not using the time on your clock? Then slow down and think. Moving too slowly and ending up running out of time and making random moves? Then either speed up the pace or play at slower time controls. Blundered because you just don't feel comfortable in that type of position? Too open? Too closed? Too crazy and unpredictable? Too boring? Then either learn how to play that sort of position, or learn how to AVOID it.

Start off by learning basic chess principles. What to do in the opening? (develop your pieces, control the center - preferably with the pawns, castle early etc.)

Basic rules and principles for each piece like "rooks belong on open files", "knights must look for outposts", "bishops need open diagonals." etc.
Learn endgame principles like "activate your king in the endgame." Learn basic king and pawn endgames, basic rook endgames like the Philidor and Lucena positions etc.

Solve tactical puzzles regularly. (If you look at my profile, I try to solve them every day. Sometimes I'm too busy and may miss a day, but I try even when I'm tired).

You can also check out a few of my blog articles. They have useful tips.