Be ready to walk up and down hills A LOT. The park is beautiful and the train makes a good place to rest during the day as well as to travel between the villages. Rhine River Cruise is also a great place to relax and get photos. Coaster lineup is all good, with Alpengeist and LNM being my favorites. Food is decent, but over priced. I'd suggest all day dining plan if you're spending the whole day there, it can be a decent savings and lets you try more. Trappers Smokehouse is always good, Festhaus is good but not as great as it used to be, Marco Polo's is a great place to grab a bite as well. If you decide you want to do Quick Queue you can purchase day of, and sometimes for single attractions so if lines are long there is a way to get to ride everything. Pantheon seems to still be temperamental so if you see it open, do it while you can, it seems to go down periodically throughout the day from what I'm hearing. Shows are decent with Celtic Fyre being the standout. Drink cups from the Florida parks can be used there for the discounted refills, but their refills are more expensive than Tampa and Orlando. If you do all day dining you can get the refills all day as part of it.
Hopefully you have time for Colonial Williamsburg while you're there, it's a great place to visit as well.