I would avoid Carnival cruise line.
If the balcony upgrade isn’t a lot more money I recommend getting it.
Cruises usually get cheaper the closer to the date of sailing. Flights get more expensive, but if I remember correctly you can probably drive to that port.
Look at the activities planned within the first few hours so you can get what you’re interested in doing into your calendar.
You can search YouTube for excursions if you need help deciding what excursions you’re interested in.
Consider wearing a mask in indoor places like watching the shows. I personally wear my mask in all public bathrooms. If you don’t have a lanyard so you can just keep your mask handy around your neck I recommend getting one if you plan to use a mask at all. Most people don’t wear them anymore, I realize that. If you get sick on a cruise you can wind up quarantined to your cabin, which is no fun.
You’re expected to tip at the end of the cruise. The housekeeper, waiters, I can’t remember who else.
Read the fine print if tips are included or what fees are added on.
I like dinner either open seating where you can go any time, or the late seating. Usually after being out by the pool or out on an excursion all day, I like to take a nap! Lol. The early seating is usually too rushed for me and interferes with my siesta.
If there is a dressy night at the dining room you can skip it if you want and eat somewhere else. Some people like the “formal” night and some hate it. It’s not really formal technically, but men are usually expected to wear a dinner jacket. More to pack.
I really like cruising. Enjoy!