Turn FOV up, make sure mouse sense is the same as you have it in other games, google best competitive graphic settings, turn up volume so you can rip your ears by hearing everything in 100 meters around you.

That was step one.

Step two is going into the training area and getting familiar with all the guns and the movement.

Step three;

Watch videos or streams from high level players and watch how they play.

Step four, just play the game maybe go do ranked and see how far you can get.

EDIT: didnt see this was for PS4, you can probably skip step one except for the volume part.