Yes, I have heard people say they were sleepy, or felt sick. I know it effects everyone differently. I didn't feel sick or tired at all. My arm wasn't even sore. Hayley's (kid) arm was sore the next day, but no side effects other than that.
Hope it all goes smoothly for you!
I got both doses of the pfizer vaccine a couple of months ago. A high school nearby had extras and I waited in a line for a couple hours and got it. The only side effect I had was a sore shoulder for a couple of days. It didn't help that I worked out legs and shoulders before getting both doses lol. Never felt sleepy or run down. My mom who is 60-ish (I think) felt a little run down the next day but that was it.
I got both of mine (I work in the school district and with students) and my daughter (13) has gotten her first one.