It really depends on the kind of learner you are. Some prefer websites (like codeacademy) and others prefer reading. I like textbooks because I can flip back to a page and review the code faster than rewinding a video. Also, I think any textbook or course will work but try to find a fairly recent one, like within 3 years, since computer science is an evolving discipline. A key part is actually downloading a compiler and writing code. Don’t shirk on that. Asking for recommendations and advise from ap cs teacher is definitely good. If you get close, you could ask your teacher for a letter of rec in the future. Regardless, the most important thing is to get started ASAP. All other points are more trivial.