There is a local quilt retreat here once a year and I have attended 5 years now. Things that I learned:
1. take a camera, fan, phone charger, ext. cord, extra light, small cooler, water, and all your sew accessories including several colors of thread.
2. don't do cutting there, cut before you go and do simple sewing. nothing too technical. one year I took a buggy barn and easily got all my blocks sewn in one day. this year I took a lot of machine applique so I could machine applique (blanket) stitch around it.
3. go as early as you can and save places for your friends. make your friends sign up--it is so fun to be together!!
4. take a comfortable chair or extra padding.
5. sign up for at least one class a day--you learn SO much even if you already think you know a lot!!