Hello, I am new to the 8notes scene, this is .y first post. I have a question regarding what the difference in levels of a clarinet player is. What is the difference between a beginner, intermediate, or advanced player? I am in my freshman year of high school, but I can play until super E, and can do some pretty advanced techniques, but because I am in a high school band, never need to use them. What would I be, advanced or intermediate, I want to know so I can seek a private lesson instructor.

Your level is as given by your highest grade pass. What is it? Are you grade 5 or above? If you don't know then how can we tell you?

Almost impossible to truly answer this question. Well, beginner is obvious--first year or so of playing. Intermediate--I don't know. Being a more accomplished player is in relation to what? If you're say a sophomore in HS and have been playing several years and can play well in the altissimo register, you a probably very accomplished compared to the average HS player. If you are talking about the possible hundreds of thousands of players capable of auditioning for a major (or not so major) symphony, that's a whole other area of "advanced". I think once you get to a certain level you can pretty much play anything that's written. The difference between such players is one may learn a piece with less practice than the next person.
For most of us there is always room for improvement on one thing or another.
Though I don't think you would be ready for my "Most Advanced" book mentioned here on the forum, you can go to the publisher's website and check out some interesting "advanced" techniques.

Impossible to answer unless we know your grade.