I've been trying to learn from online sources, I've managed to learn some scales and basic songs but yesterday I managed to hurt my left hand while playing scales, so it's time to learn good technique. Can you guys please help me out? to be honest, I can't even define a good technique, what is it? and how should I practice in order to archive such thing? Thanks and sorry for my mistakes, I'm still learning english!
Stop scales. They are not "beginner things" because of what is involved.
The famous pedagogue Abby Whiteside [clip unneeded information] said scales are not for beginners, they need to be more advanced before there is any benefit.
So, you can play a lot of music that uses a lot of scalar passages, and still not be a master of running scales in an academic fashion.