What helped you improve the most when learning?

I have been playing chess 20+ years without learning

I play 1 or 2 rapid games each day and thoroughly review them. I play only 2 or 3 openings, and to study the lines, I built lichess.org interactive studies using titled player games from youtube. I do puzzles - on lichess you can play puzzles by opening, so you only solve things that you would actually see in your games.

I swear this isn't an ad for the competition. On the chess.com side - I mentioned reviewing games. I'd recommend turning off "show best move". Seeing the best move doesn't help you get better. What helps you improve is seeing that you made a mistake, then taking some time to think about what you should have done instead. Then play that move and see what the engine thinks.

Taking lesssons is by far the fastest way to improve. That’s what I did to improve. Now I’m showing other players the ways I used to improve, If you want to hit 1000+ you can message me for more details.

Tactics training, and developing a decent agressive opening repertoire.

Going over all my games won or lost with someone better or an engine and not accepting their advice on every move but questioning it and asking why, then deciding unless an absolute mistake whether my move maybe not the best fit into my playing style and will continue to play it.

Two out of three is very good. I do not have an opening rep matter of fact only know most of openings I play out to 4 or 5 moves after that just think and play chess. Actually have no idea what their actual names are.

Learn to use the engine correctly instead of just looking only at its first suggestion and eval.
and learn to use the lichess database correctly and analyze the statistical data correctly.
You will get far more out of those 2 than all the other resources combined.

Go over your game and think of what the best move was, check your answers with an engine, and make sure to find out why

That's a great question.
My answer:
 
I think reading through a collection of games by famous players helped me more than anything else at all - I played through first Lasker's then Rubinstein's collected games (just bare scores) - I did not know the results of these games as I played through them - trying to guess and analyse as best I could. I also made notes (in a book), then checked them against annotated versions. I worked through about four or five games a week for a couple of years - one and off - made a HUGE improvement.
I did this on a real board - and that was important as well - it is just too easy to 'skip' stuff using a screen. 
Rubinstein's games were SO simple looking - Lasker's not so much.
Of course; You also have to learn all the basic endings that come up in the games you play through and revise 'em. 
If I were doing so again today as a beginner - I think I would choose a player like Adams and Kramnik - two totally different styles. 
I agree that tactics training is important but NOT AS IMPORTANT as strategy and endings for a beginner.
Good luck with your chess - don't confuse BLITZ with real over the board league chess using a real board.

My older brother, books and other advice from stronger chess players. 🙂🙂🙂🙂🙂🙂

Before I started playing tournament chess, I read everything on chess I could find in the library. I must have read about 20-25 instruction books by Chernev, Reinfeld, Horowitz, Fine, Lasker, and others. I also played through many hundreds of annotated master games in books on famous tournaments and games collections of famous players.

i won the unrated prize in the first regional tournament u played in

I strongly recommend studying books as a way to learn and improve. It worked for me.

I wouldn't know. I haven't learned yet.