Can a primary care doctor assess me for auditory processing disorder? is there a point in knowing i have it? seems like not covered by insurance.

Yes and no: Generally speaking, a primary care physician (internist or family physician) can at least begin the workup of your problem. Whether they can complete the assessment depends upon many factors, and you may need to be referred to a different specialty for that. Either way, you should go to your pcp first because they can at least choose the right specialist if you need to be referred.

You already know: Each person processes new information in their own way. Some are visual learners, others auditory, some tactile, some musical, etc. For some people words on paper are meaningless, but if spoken, the words become clear. For some hearing information is meaningless, but if written or drawn, the information becomes clear. Learn your own methods for learning. A learning specialist may help.

Hard to say: Categorization of your learning style may or may not benefit you. The testing is usually done by educational psychologists that select the type of testing that show your learning strengths & weaknesses. The one on one testing is time & personnel intensive so it can be quite expensive. It is rarely covered by insurance. Labels don't matter. People learn how they learn & avoid their weak inputs.