I can understand the problems of a student who is preparing without any coaching! Even I have used YouTube for clearing my concepts and to get good hold of them. But the main key is ‘Not to forget the main purpose why you are using YouTube!’ Just like every social media, even in YouTube you can get easily distracted. So beware of it!
Some of the best channels that I have used during my preparation are,
Physics –
1) Physics Galaxy (Ashish Arora Sir)
2) Physics Wallah (Alakh Pandey Sir)
3) Sachin Sir Physics
Chemistry –
1) Dushyant Kumar Sir (Helios Educore) for Physical and Inorg. Chemistry
2) Vineet Khatri Sir (ATP Star) – Org. Chemistry
3) Sachin Rana – Org. Chemistry
Biology –
1)Vipin Sharma (Ozone Classes)
Just like everything in this world YT have positive and also lots of negatives in it. To get best out of it, focus only on watching the content that will help you grow and succeed in your preparation.