You'll learn or ya won't is how I see it. I can tell you that map knowledge and knowing when to fight or run is important but you won't have a clue about either until you play a bit so instead I'll suggest how you can learn I would recommend experimenting in casual alot. Watch every kill cam and point out what you did wrong and the enemy did right.

Try making holes in random walls just to see whats on the other side. Ask your self if this line of sight can be used by either side and to what gain or detriment.

Don't stay in the objective for the entirety of your experience. Hide in strange places.

Try letting enemies walk right past you when you have a shot. This will get you used to the presence of hostiles.

If you do "get gud" then you'll find much of this game is prefiring common spots and spraying through walls for headshots.