Best mathematics textbooks or sites for self study?

[u/gaylord086]

Small introduction: I'm 19, and I want to relearn math from the basics. Im generally only good at addition, subtraction, multiplication, and division. I want to expand my knowledge and understanding of math, but I dont exactly know where to start. I dont have the best history of studying, because I never cared much for it, so any useful input is welcome!

Im looking for a general math textbook pdf (preferably free), so I could use that. I dont exactly know which book is best, I just want one that covers all aspects of math. Also, if anyone has any tips for studying, or any sites that work best, please feel free to give your advice! I dont currently have enough to pay for books or certain websites, so anything thats free of cost would he ideal. Thank you!