How to get better in chess


- Find solid opening for White and for each of White's main replies (one for e4 and d4)
- Analyze your games after you played them and find your mistakes (free if you play on Lichess)
- Watch chess videos on improvement (Chess Vibes, Chess Coach Andras, Chess Dojo, Chess Geek, etc.)
- Play long time controls (rapid games or longer)
- Do tactics and puzzles everyday (preferable from a book as they are human approved)
- Create an opening repertoire on Lichess for your openings so you can prepare for certain openings
- Find Short & Sweet courses on Chessable for your openings
This is the free way of improving at chess. Some of the lessons are good on chess.com but some of the presenters are boring like Keaton Kiewra. If you were interested in taking the lessons, create a Lichess study for that series and find the games or play the moves into the study for future reference.
I would play on Lichess as it is free and gives you the tools you need to succeed including their very own lessons.
But if you really want to spend money, Chessable is a great resource where you can look at their free courses and decide if you want to buy the full package. There are also some great strategy books like "The Woodpecker Method" which will improve your pattern recognition (recommended for 1200+). Or you could get a coach who might teach you a few concepts and/or go over your games with you. Or if you are 1500+ and really serious about being a titled player, buy Chessbase, the best tool for chess improvement but only if you are intermediate+.

Improving Your Chess - Resources for Beginners and Beyond...
https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond