Insight Needed

I am stressed because I have been avoiding the doctors for years and now I need to go in to get my Tdap vaccine (already stressful enough for me). The last time I had a proper checkup was when I was 4. Can you guys provide me some insight as to what I should be expecting to experience? For context, I’m a 16 year old female and I live in Canada. I’m 5’6, white, and about 145 pounds. No outstanding problems and in the past I’ve just been to the walk-in clinic when absolutely necessary. I’m occasionally a bit fatigued and have always had a screwed up neck that causes headaches. I am hyper mobile (told to me by my physio) and have a screwed up wrist from an old injury. What’s listed above are more long standing issues that are manageable but I don’t have anything concerning going on. I have never had labs done and have gotten all my vaccines other than the Tdap that I would be getting at that appointment. Thank you everyone and please don’t sugar coat because I need to know the truth of what I’m getting into. Please let me know if you have other questions that could give you a better sense of what would realistically need to be done.