For the first few months, getting better at the game is primarily a matter of reading maps better. At first when you play 3 star maps, you will probably think that there is too much stuff going on on the screen and it will be hard to decode, but eventually those same maps will look like slow-motion. That's what the ability to read does.
You get better at reading by playing a lot of different maps and by pushing your limits. If you can't make much sense of what's going on on the screen, you're wasting your time with this map. If you can mostly read what's going on but you die at some point, I think that's a pretty good place to be. And it's fine to repeat some maps if you like them a lot, to practice technique, but most of your time should be spent playing a lot of different maps, regardless of whether you pass or die.
Also pay attention to the timing circles, they show you exactly when you're supposed to click on the actual circles. They help a lot.