The biggest problem I have faced, by far, is PROCRASTINATION. I sit and sit but don't DO. How on earth can I expect to earn any money by doing that??
The second biggest problem I face is not ignorance, it's knowing a little about a lot. It is confusing.
Do your research, find what you are interested in and FOCUS on that. Too little information about too many things can only lead to your brain feeling like swiss cheese.
PERSISTENCE. I have been guilty of trying something and if the results aren't quick, or I haven't given it my all, I give up and move onto something newer and shinier. Make sure you have given it you (truthfully) best shot before moving on.
PLANNING. Fools rush in.
Anyway, just my two pence worth!