Dear Pritam,

IIT JEE is the India's toughest exam to get a admission in highly reputed colleges to pursue Engineering. You need a concentrated mind to get that place, definitely you need different different platforms to continue your preparation by own, there are lots of YouTube channels which provide you the good knowledge absolutely free, and some will charge for the same. If you have completed your 11th and 12th in a good manner then yes Alakh Pandey sir Physics note are good to boost your preparation, try to attend their Lectures as well for better explanation.

It would be more helpful if you focus on only one platform, there is not need to rush here and there for the same topic, they will made you more confusable. Try some coaching notes as well for problem solving and concept clearing only. Solve for and more problems to get the best output, here I'm providing the link for the most useful books to crack IIT JEE. https://engineering.careers360.com/articles/best-books-for-jee-main

Best Of Luck!!!