Good advice above. It is very doubtful
that you will get seasick. amidships is better if you are concerned. Also if you are concerned go to the the drugstore and buy some Bonine (meclizine). Very effective.
The best thing about cruising is enjoying the scenery coming into and sailing away from port. For that reason, if it works for you, get second seating so you will have plenty of time to clean up after being in port all day, change and have a drink during the sailaway before
dinner. Being stuck in the dining room for early seating during sailaway is bad news. You miss a lot.
Also unless you just don't like your fellow man, ask of a table for 6 or 8 you are likely to make long term friends. We have had wonderful
table-mates over the years!!