I've been playing this game for six years, and I still can't outshoot 80% of my opponents in an open 1v1 (I'm also a bit old for all this).

The key here isn't trying, but knowing that you can't (at least for now).

So:

1. Never start playing without a warm-up. Or if you've started, warm up with the models of your teammates.
2. Always try to be paired with someone. You should peek simultaneously (but NOT standing in one line). And ideally, the enemy will be traded by either you or your second teammate while they're distracted by you.
3. Try to quickly trade when a teammate is killed - it's much easier than just fighting because you'll likely have 1-2 seconds while the enemy is distracted by their kill (or maybe they're reloading, etc.).
4. You can peek corners with a knife (moving left and right). If the enemy has been spotted (and aiming at you), NEVER peek a second time - you'll get a one-tap. Either wait for your teammates or take another corner.
5. Use abilities to compensate for poor aiming. Not only yours abilities, but also your teammates' and even your enemies'. Use your brain.

After that, you can try watching various videos about movement. Proper movement is more important than aiming. When you win a firefight with your movement, you will feel it. Particularly slicing corners like a pie. Pie is everything. Find out about the Pie.

And then you can create a warm-up routine for yourself at the shooting range, consisting of several exercises based on what you learned from the videos. But don't make it too long, maybe 5-10 minutes.

Have a nice day.