Thank you, this is super helpful and informative. Another question if you're up for it: How important is knowing scales and arpeggios? Should I focus on learning them all now, or is it not worth it? I do have some basic knowledge of this subject, but nothing past the fundamental level.
Scales are incredibly important, but my advice to younger musicians is, don't go nuts trying to learn hundreds of them! Learning the 12 major scales and 12 minor scales is all you need to get started. By "learn" I mean, you can play these 24 scales over the entire range of your instrument, you know the names of the notes, you can identify key signatures and know how many sharps or flats are in each key. Bonus points if you can sing major and minor scales, and if you know the pattern of whole steps and half steps!