If you want to re-learn chemistry from depth, then I have the perfect roadmap for you. First pick up the books of class Xth, there the chapters of Metals and Non Metals, Acids Bases and Salts, and Carbon and It's Compounds are very important. Especially Carbon and it's Compounds form the base for the Organic Chemistry of class XI and XIIth.

Now when you move to class XIth, then you should first read all the chapters from NCERT, then attempt to solve the back exercises. You can also solve the Chemistry's Modern ABC. If you do this then you preparation will definitely be complete. All the best!