I would assume you have some basic knowledge but trust me, as you get better you'll understand how little you know right now. My suggestion is to first improve your basics - stance, stroke, tangent line, and speed control. Give each one some dedicated time - real dedicated time, no TV, no music, no buddies watching you, etc. I've listed some videos below, some may work for you and some may not, just search YouTube and ask questions. Go play in some local tournaments. Work on kicking and banking, learn how to shorten and/or lengthen a bank/kick using speed and English. Learn 3 rail kicks/banks, learn what spot on the wall is.
The first two videos below are BY FAR the two videos that helped me improve the most. Also, kick safe is great way to learn kicking, safe's and speed control.
Work on your stroke...
Work on the tangent line...
Work on speed...
Work on safety play...
Kick Safe...
https://www.youtube.com/watch?v=zwCzW3K4sA8
Work on your break...
Not sure what game you play so no link as each break is different, just search YouTube, you'll find something.
Play as many games as you can to improve every aspect of your game.
8B
9B
10B
1P
14.1
Banks
Kick Safe
Rotation Pool
Etc...
Good luck...