u/ImpossibleParfait973

I'm in school and we haven't been taught calculus yet(we're not learning it this year) but it interests me quite a bit, so i was wondering how do I learn by myself. Like do I watch YouTube videos, or are there any specific textbooks(preferably online and free) that I can use. I know basics of math, but is there something else I need to learn before going ahead? I'm also probably underestimating the difficulty level of this, but I'm excited to try.

EDIT: I am completely new to calculus, I know nothing relating to the subject.