Hi dking67, and welcome to cruise-chat.
Are you going on Carnival Triumph to Halifax and Saint John? We've done that route several times, twice on her sister ships. It's hard to predict the seas in this area. But yes, in general it's not as smooth as the Caribbean (although we've experienced rougher seas in the Caribbean at times), so you're wise to be prepared.
I'd make the green apples and/or ginger tablets your first line of attack. Then, grab a deck chair amidships on Deck 3 (exit through the main lobby) for some fresh air and a look at the horizon. Most pax don't know about this deck and head straight up to the top of the ship. Being closer to the waterline will be more comfortable.