you're either reading wrong or have bad sense of rhythm.
to help with rhythm, play maps with easier patterns so that you can focus more on timing, instead of trying hard to read or aim.
to help with reading, play maps with patterns you struggle on, but keep a good rotation, retrying and missing the same part just makes the misread a thing of habit, and that's no good.
I would also personally go in that order, after you play longer and improve you'll be able to diagnose your own problems in the game, and this'll become way easier.
I've also done things like not use hitsounds for long periods of time, which won't help on low star maps since they don't tend to follow the music too strictly.