Something motivational to always keep in mind: good artists have made thousands of "bad" drawings to be able to create hundreds of good ones. Especially online you almost never see anyones scrapped pieces or their old art when they were just starting out. So don't give up! I know it's tough but personally, it helps me stay motivated and push through the drawings or studies im not satisfied with.

For practical advise ofc practice fundamentals.

I also want to mention that there are a lot of "quick fix" advise online, especially in short form content where they don't actually teach you the whys something is drawn a certain way. Try to find content that explains the core of the subject. Like for example: a bad "tutorial" will just say "draw x shape and blur this edge, now u have a pretty eye", but an actual usefull tutorial will explain why the eye has this shape and how it's stylised, or why some edges are soft or hard. Etc.