Bring a camera, take lots of pictures. Maybe think about ways to ask questions you may not have gotten answers to in your letters. Some things to think about: Family pictures are triggering for us, it makes sense that they might be triggering for b-mom/b-dad too, so you could bring pictures of yourself growing up, but I'd ask first if they would like to see them. Plan an excuse for a break, you don't have to use it, but it's nice to have one just in case you find yourself feeling overwhelmed. Are you bringing a support person with you or going on your own? Is it a day thing or an overnight thing? Will there be lots of different family members or just b-mom/b-dad's immediate family. You may find that you might want some alone time with b-mom/b-dad. When I first met my b-mom I was so focused on her that she might as well have been the only person in the room. It's really about what will make you feel the most comfortable. It's a big step and good luck!
I met my birth cousins and family last year. They knew nothing about me or the adoption. When they invited me to there family reunion I say “yes” and moved mountains to get there. They lived in rural Missouri. Nothing like any place I’ve ever lived or visited. It was surreal. I couldn’t sleep for 2 days before. When I met one of the cousins it was great at first. They lived very humble. She was nothing like me. After about 2 hours, I felt a deep dissatisfaction or let down? Has anyone else felt this way. I pushed it aside and really tried to just live in the moment and get to know these people, my birth family. The feeling went away and I ended up having a good time. The cousins said they felt connected and a few invited me back to stay longer and get to know each other. My suggestion is to be there in the moment and don’t over think things if possible. And good luck, you’ll be great!