To become a GM is 8 years of hard work.
You tube is no good: that is passive learning.
chessgames.com and 365chess.com are free data bases, but you have to put in the time and effort to study the games yourself.
Kramnik worked 10 hours per day, 7 days per week and studied 10000 games per month.
Which are the best websites that provides free chess course on you tube ?