I was legit about to say play more before reading ur post
Anyway yea you just need to practice more with different weapons etc, try different sensitivity settings..this is important if you wanna preform well, try not to go too high with the sensitivity, just keep trying different settings till you find one that suits you or one that you think you're playing better with, once you've accomplished that just keep playing until you get used to it, there's plenty of game modes in csgo you don't have to keep playing competitive especially since you're new to the game, it'd be better if you just practice in other game modes before diving into competitive as a newbie, you could practice against bots, you can play on community servers which involves stuff like 1v1 servers, awp only, and even community made competitive servers that doesn't affect your rank.
If you want to know the mechanics of the game i'd suggest looking for tutorial videos (like how guns work and even how to become better at the game and play properly) on youtube or something, they would do a way better job at explaining stuff than me.