Congrats on your first cruise, just remember there are no
stupid questions here, we've all been in your place at one time. As for ordering for dinner, the waiter will get everyone's order at the same time, they will wait until everyone is at the table.
You can order wine by the glass or by the bottle and if you and your husband order a full bottle and don't finish it, they will save it for another nite, just let them know when you want the rest of it. Its sometimes nice to order a bottle and share it, then take turns. That works out if everyone like wine with dinner. I've had a few where I was the only one drinking a glass of wine for dinner, so I just ordered a glass when I wanted one. Either way should be fine.
I've found in most cases we all finish dinner at the same time, if not, yes feel free to excuse yourselves from the table. Have done that once or twice if we wanted to catch a show.
Feel free to post any other questions you may have, there is always posters that can help you with them.