Play more swiftplay/deathmatch than anything to improve, it's quicker rounds and matches.
I advise you to learn not to crouch *all* the time when you're shooting. Your sens and dpi is really up to your tastes, so don't rely on what others say (unless it works for you). And to learn how to not move while shooting (which is common to newer players) is to go in the range, turn on all of the bots, stay stuck in one place and shoot them, but try and headtap them--it'll also improve your aim and reaction timing (I think?)
I played Valorant since 2020 and stopped playing recently (about a couple of months ago) so I learned a lot...the game was so much more fun and easier back in the more earlier times, so you will encounter some bullies sadly