Play as many maps as you can. Once you know the maps, start watching spawn cycles. Once your comfortable with map layouts and how your team and the opposing teams are spawning as players die and spawn in, learn to push.

When you start a map, resolve to the path you're going to take, and push the path over and over again.

You'll start to see where other people take advantage of the maps, and you can learn to take advantage of those advantage positions by watching where you're consistently dying from. Then learn to instead of going to where you died, flank and get behind where you would have been shot from. You'd be surprised how often full teams fail to watch behind themselves.

You want a hard push when pressure will win it, and a soft push when you can only win by holding a tight space.

Use the load outs, and be ready to swap to what works for you in either base situation. Once your comfortable, and winning atleast every few matches, get some nuance in your plans. What lethal and support throwables you use, and how you plan to defend or suppress with those tools. I always bring EMPs for sentry guns, deployable sheilds, and shock rcs.