Need advice from people my age or older (16-17-18-19)

I don't know how to start this exactly. But, basically, I don't know what's gonna happen with me in the future, like, I genuinely don't think I even have one. To clarify things, I'm not depressed or anything, I just feel like I don't have a future simply because of my grades and the fact that I skip school a lot (and some other reasons). I try to be positive that this is just a phase and that everything will get better but lately I've been thinking more and more about the fact that I lack basic knowledge on certain things that I think are important for me to operate in life and that scares me very badly because I don't know how to change or who to ask for help, or if I will ever be able to learn what I wasn't able to.

Well, more than advice, I'd like to know if someone is going through the same or something remotely similar because I'm losing my mind thinking that I'm a complete disappointment without a future