Hey, as you know already from the title, I'm new to Bitcoin, I would like you to help me by telling, where to buy, when to buy, where to sell, when to sell, things like that.
Important: I'm 17 years old, some methods may not work if I don't have 18, and that's what I have noticed.
I hope you can help me get started.

Edit: Thank you guys, your information is helping a lot, I already have a wallet, feel free to help me
1KnWzEdJgAmE3rB3Xax8sDfydnikguxrhhWelcome to the crypto world. As a beginner, I suggest you to read more, ask questions and understand about bitcoin.
As for buying bitcoin, you can try peer to peer exchange such as localbitcoin and the marketplace of this forum. Some sellers dont need identity verification.