Thank you for asking! I'm not exactly sure what I want to specifically specialize in (I'm still trying to figure out how to get through high school without being trampled), but I do have a few things I find pretty interesting and that I catch myself studying with no apparent goal in mind.
I think transcription (sounds -> symbols) is very interesting, especially when it comes to languages with previously-created symbols and the romanization of them, like Chinese Pinyin. Other tonal languages are interesting too, because they often need specific symbols to represent the tones. I think it's also interesting how there are so many languages that still haven't been recorded, and I hope to maybe possibly be someone who helps to preserve one of them by aiding to record it.
This brings me into phonetics, which I also enjoy learning about, if you can count "finding it interesting enough to distract you from homework" as enjoying it. In actuality, I really do find it interesting. I sometimes space out and start trying to make the sounds I'm reading about, which I think would be good if I were actually going to learn a language instead of just read about it. Because it concerns the way sounds are made in the human body, it also feeds into my love of anatomy.
I also make myself to read a bit about syntax (and other things related to how languages are formed, like morphology and semantics and such) to help me build my conlang.
Sorry for the rant...I don't have much of a set path for what I want to do, so I just kind of...read everything I can get my hands on.