I think one of the best advices I can give is to try Gesture Drawing: it helps with anatomy of your drawings and I noticed a great improvement in my drawings pretty quickly and I've been drawing for a good 15 years.

It's where you look at a pose and try to replicate it in 10 seconds. Here's an example


You have to do this a lot, but once you do, doing poses becomes second nature and easier. And best of all you can apply this to any character you want!

And as for using references, Use them for studying and developing your own style. It helps to find what style you like and makes making more art fun.

Also it's okay if you're not good now, learning from you're bad art is how you end up making good art.

And Always experiment! Try new things! it's helps a lot!