Find an opening, study it and stick to it. If you're playing rapid you don't need to play fast so think ahead about your moves. Also do lots of tactics/puzzles.
Im locked at 300 elo 💀 in rapid. How to improve and get better fast ? I

You have to remember to control the center and develop you biship and knight When you make that you have to castle you king to be more safe
The most important thing is to do more tactics and lstudy more the middlegame and review you games and learn from your mistakes
I suggest you to play the italian
ppiening because is for begginer, amateur and for chess master

also, there are many people who like to help people improve for free. just look around in beginner forums and stuff.

top first one right beside images
Does it works ? it took the last game i won

the game was fine, you did not make too many mistakes, but you didn't make any tactics or anything like that.
I think i play too fast but idk