"I just graduated from high school, what should I do now?"
There are some things to consider first.
1. Muhammad, pbuh, said that no one can take away the knowledge you're destined to have.
2. Self-directed learning is the highest form of knowledge, and in India the highest recognized scholars are self-taught.
3. There are free courses, videos, and lessons online in every field often done by some of the brightest minds, and textbooks for sale online.
4. Study one course or book at a time. Separate books that require study from books just for fun.
5. If you decide to go down this path, know that it is governed by motivation and this can change direction, often in conflict with true will, so be patient. Sometimes it can take years to finish a book.
6. I knew none of this when I was your age.