As you want to prepare for jee advanced 2025, then I can assume that you are in class 8th and you will go to class 9th in 2021. And you will pass your board exams in year 2025.
Now an early prepration of these national level exams are very good sign of interest. And if you prepare early there is a chance that you will become a diamond in coming next years in field of jee advanced. Many students start preparing fron 6th class or 8th or 9th class, for getting best results in jee advanced.
So, you can also prepare for jee advanced 2025. You can join some coachings or you can start early preparation by self studies. Some of the good books for foundation courses are - IIT foundation book sereis by Pearson or TMH.
You can complete the book hc verma in class 9th. And read higher classes books in your current class.
So start preparing early to get a good ranks in jee advanced and also note that, if you are serious for jee advanced then definitely you can succeed.