My first internship opportunity, and I don't know how to tell them I have trips planned

I would like to preface that originally I had not intended on starting an internship, but a more than fantastic opportunity arose and now I'm regretting the trips I booked. I've never had a "real" job yet and only held part time retail work, so this who experience has been anxiety inducing.

I'm wondering how do I tell them about my trips. They are asking for my Fall/Spring availability and I have one planned over the entire week of Memorial Day, and one 4 day trip in August. I know they do have hybrid work and I am more than willing to work through my vacations, but I can't help but feel like this will make them decline me. Has anyone else had a similar experience?