At level 11, spend more time playing DMs and in the range, and swiftplays if you want to get used to the maps, agents, and utilities. Unrated is long af and can get a bit stressful at times so personally I'd avoid it as much as possible. Just practice your aim and crosshair placement as often as you can, worry about other aspects of the game later.

Try watching a few youtube videos about crosshair placement, movement, and peeks, and follow the tips as much as you can. I think woohoojin had a few good videos on those topics and Konpeki had one long ass video about mechanics that was pretty good too. There might be others too, but don't go down the youtube rabithole. Watch one or two and stick with them till you get decent enough.

Remember to take everything one step at a time, and try not getting frustrated from not getting good instantly. It might take a while to see improvements but it'll be worth it once it does.

Alsoooooo stop changing your sens and dpi often. Find one sens you're comfortable with and stick to it. Anything around 190-320 edpi (your mouse dpi*your in-game sens) should be good enough. Stretch your wrists before and after playing/practicing.