Imagine me as your younger brother, what advice would you give?

I'm 17 and going to start my college life. I would really appreciate knowing from those who have been at this stage before, what did you wish you had done differently when you were 17 years old? What would you say to your past self regarding life, relationships, studies, and profession?

I will be learning Computer Science and my aspiration is to be working in one of the best tech firms like the rest of the people (FAANG or any other). Any advice on the best way to prepare, skills to learn, and how to differentiate yourself from others in the field would greatly be appreciated.

If you were able to turn back to those days and advise your younger self, what would you say? What are some things I should avoid doing, and what are some good habits I should develop early on?