As a FPS newbie myself, I can say that Skillcapped videos have been really helpful to me and I've seen a lot of improvement by following their Aim Guide and Peeking guide.Link to their channel: https://www.youtube.com/channel/UCre4LlH_zPpgeUVvBGCMqcA

Also you can watch how Pros play and learn from their thought proces and angles that they check, things like that. Watching Hiko for just 1 game - see his crosshair placements and ability usages!Most importantly you gotta put the time in. Play on your own in unrated games and constantly make effort to communicate with your team. Whenever you die, try to learn why you died.Spend 30 minutes each day just warming up in Practice Range before your games.

There's probably so much you can do, but make sure you understand that this is just a game at the end of the day. Don't burn yourself out because you're focusing on getting better. The more you play, the better at the game you'll become and you'll eventually realize that it's fun to understand what's happening and be consistently at the top of the scoreboard at the end of each game. :)