I've never been on a cruise before. Does the ship move much? Will I get seasick?
Cruise ships are quite large. You may feel some motion but the anti-roll thingies keep the ship steady. People wear those dots behind their ears if they feel as if they will get sick. Bring some with you because trips to the ship's doctor cost extra.
The best thing to do is to get on the ship and have 1 drink, not 47 tiny-umbrella-fruit-juice-I'm-on-a-Cruise!!!! drinks. It's fun to watch people climb up the plank and race to the restaurant to eat as though they've never eaten before, then hit the bars and drink until they are stupid. I think those people get queasy.
I get a tad peaked when I go sailing with St. Casserole and she is at the rudder. She is a faulty sailor, at best. I think you'll do fine on the big cruise ship.