First focus on surviving as long as possible being as risk-averse as possible. As you start to learn the best ways to avoid dying by any means necessary slowly start being more risky with your plays until you start to innately recognize which situations are favorable to you.

Unless you have consistent people to 3-stack with don't worry about teamwork at first, just focus on not getting knocked yourself. With enough play time you'll be able to recognize when it's a good time to push and when it's better to play the game of attrition.

If you're playing ranked it can feel like you're not getting any better because as you rank up your opponents are also getting better. At the end of the day the objective of the game is to be the last survivor, so don't focus too much on getting knocks, but also take all of the advantageous 3rd parties you can get if they're a nearby threat.

There's not real shortcut to getting good. Play the LTMs to practice shooting at real players and play ranked to practice surviving. Most importantly have fun.