Hello, is it just a simple hobby for you to learn sketch? If it's just a hobby and I want to spend five years studying, I think time is enough. The teacher's estimate is 1 year, and the rest is for you to practice by yourself. In fact, I personally think that talent is not the most important thing in painting art. As long as you are willing to practice hard, you can still paint well. As for the general kind of studio, I suggest not going. The studio mainly teaches students to go to college, so you really can't learn anything. If possible, go to the university to find an art teacher.