Your question is not easy to answer. Frankly, though I never like to write this sort of thing, it makes me more concerned about your son’s teacher than about your son! What does she mean by “good skills” but “trouble understanding questions”? Understanding ever more complex questions is a skill that should be developed during the kindergarten year, not necessarily mastered ahead of time. The example you give about his assertion that his drawing represented a picture of California is actually quite mature. He may have assumed that when he explained that it was California, he had answered her question. Most children label their drawings as objects or people in their immediate world or as a replica of some toy or something they have seen on TV. To characterize a drawing as a map is advanced for a 5-year-old.
So I would request an appointment with his teacher and ask for more evidence that he is not progressing properly. She might have chosen a bad example and thrown in that statement about “good skills” so as not to upset you. Ask her for other instances of what she means. If she can’t give you any others, then I think you should feel quite reassured. If she does, you will want to consider whether you should ask for an outside opinion. May I suggest you look up my article on this web site entitled, “Is Your Child On Target? Part II.”
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.