Sheet music is important. Practice more so. I'm not as visual when it comes to music and sometimes get stuck on sheet music until I hear it once. Then it clicks.
Try Karaoke sheet music if you get stuck. I wish I had this as a kid. I found a book of music I have in the closet but this is better. They play it a little slow and it's a relatively easy song to pick up.
Find what you like and practice the crap out of it. Scales I hated, but practice the crap out of them too. Because once you get to the improvisation stage you'll need a good understanding.
I had band one hour a day, jazz band 2 hours/week, and another 2-3 hours of practice/week, plus any performances. That was about all I could squeeze in at the time.