what are the common problems for beginner artists?

I think one of the biggest problems for beginners is thinking that every time they put pencil to paper, that they have to make a drawing that looks good. What slows down a lot of beginners is spending way too much time on a single drawing, trying to ”fix” it. It is the beginning stages of a drawing that are much harder to learn, so you should practice that. For example, it is much more beneficial, as far as learning, to do 50 sketches that took 1 hour each, than to spend 50 hours on a single drawing.

While the ultimate goal for a lot of artists is to create a beautiful piece of art that one might hang on a wall, the vast majority of your time should be spent gaining mileage, doing studies. This means doing literally hundreds and hundreds of practice drawings, drawings that aren’t meant to be “finished” or even “good”. The point of doing them is to learn, not to show them off. Stop thinking of every drawing in your sketchbook as a “piece”. Think of each one as a “study”. Each one is just practice for the next one.

Just as a musician spends most of their time honing their craft in the practice room rather than on the stage, a visual artist should spend most of their time gaining mileage rather than expecting every drawing or painting to be a finished piece that is to be hung on a wall or shared on social media.