Focus on your movements and accuracy and play low BPM maps to improve your jumps and cursor flow, gradually increase the BPM as you start to clear songs easily and your streaming speed and accuracy will develop alongside it. I started playing 140 BPM maps recently to try to get 99% every time and once it started to work for me I moved up to 150 BPM and did the same thing, pushing myself to be more precise in my movements and hitting the notes I'm now at 175 BPM and it's working and I'm going up on the speed almost every day. I feel I have much more skill from doing this than when I was throwing myself into really fast insane maps trying to mash it out and see if I can be accurate or not.
This game just takes lots of practice doing it slow and gradually building up, just like learning how to play instruments.
Quit honestly it's sad because I see so many people focus on streaming and they can't even do simple maps that are slow. Every time I hear someone complain about a map being too slow I know they aren't really listening to the notes and the music and are just visually hitting things. Albeit impressive it's primitive and not very effective, because it takes several tries to get high accuracy just going off of visually seeing the notes and memorizing the map. You'll have an easier time learning how to listen to the music and notes.
But hey, just have fun with this game and enjoy the music, do what you can and take no mind of what others think.