Need Help

Should i watch lectures?????? Agar Jee mains and neet dono ke pyq ho rahe hai do i still have to watch lectures or should i watch lectures????? Aur agar dekhu toh kaunse subject ke. Because i think books ke baad i can solve problems as well as understand theory then should i watch lectures. Asking for 2 years prep,should i watch lectures topic wise for the things i did not understand or full