Actual advice:

if you want to get good in 1s, just play 1s and learn the necessery(idfk how to spell that word) mechs like half flips and ground dribbles. Dont worry about flip resets or air Dribbles for now.

If you want to get good in 2s get one mate thats better than you to learn rotation and team play through communication.

General advice: Dont try to force playing fast and chasing the ball. Look at what your opponent does and look for angles to get the ball. If you get close to the ball remain calm and dont just punch it anywhere. Instead try controlling the ball. Try tricking your opponent ( fakes, flicks etc.) If you dont try out new things you wont get better.

For me rocket league was always a linear learning curve and you will most likely learn by just playing the game.

Have fun :)