I would suggest working on realism and study the human body , the muscles and how they work, and the skeletal system. You don't have to only work on how real body anatomy works but doing a little bit of sketch studies can help alot! (Especially when you want to draw in a cartoonish style) I use this format for learning when I tackle drawing a new animal, and another helpful tip is to watch others tutorials on yt it can help alot.
here's a video by bradwynn jones you may find particularly helpfulI also suggest checking out any of the artist in my sig ( excluding Amelia,Bob,and kattvalk as they don't draw/paint humans) by drawing along with videos such as these you can pick up on the way they draw, by paying close attention when they start their sketches. Aaron Blaise does alot of animals too, but he also has tons of human tutorials.
I hope this helps you!
