Watching videos is dangerous, because it's too easy to passively watch someone else do problems, fool yourself into thinking you understand, then completely flounder when you're faced with a problem that isn't exactly the same as one you've seen.
Physics actually has very few rules and formulas. Follow the derivations. Understand the methods. Trying to memorize the specific formula for each situation is the usual bad tactic used by good students. But it's an overwhelming task and leads to mediocre results at best. That's a strategy that works in most other classes, but not physics.
To get some intuition, read some easier books, like Thinking Physics.
Other ways of thinking that seem unique to physics are dimensional analysis and thinking of extreme cases. Once you get the hang of them they're easy, but they're also powerful and mysterious for the uninitiated. Dimensional analysis is so powerful that you could probably pass the class just mastering that alone. Read the first chapter of Morin, or of Streetfighting Mathematics.
Thinking Physics by Lewis Carroll Epstein https://www.amazon.co.uk/dp/0935218084/ref=cm\_sw\_r\_tw\_dp\_x\_t6nrFbN2S4MJ2
Physics concepts without math
Thinking Physics by Epstein?
Not the same cover but but those can change over time
Yeah I regret picking just one. Biology's just my personal interest. EE and CS is a classic and probably increasingly interesting with so many cheap powerful chips coming out. I think physics would be interesting as well. I have a friend doing a PhD related to quantum computing and it sounds fun.
I just realized that I missed the fact that you're a high school freshman. You've got so much time and opportunity ahead of you if you're thinking about this already. I'd start taking coursera classes (and khan academy and edx etc) now and exploring.
This is slightly off topic, but since you mention physics, I really wish I had read this earlier (reading it now): http://www.amazon.com/Thinking-Physics-Understandable-Practical-Reality/dp/0935218084
edit: I can't help dumping more stuff I wish I'd experienced earlier: check out LessWrong, Slate star codex, and HPMOR if you haven't seen any of them
And I also really wish I had started using Anki earlier:
http://www.gwern.net/Spaced%20repetition. http://ankisrs.net/. I've learned so much stuff that I've forgotten it's ridiculous.
The book Thinking Physics covers this and many others.