Congradulations, and welcome to the world of cruising! You wil find cruising to be the best value for the money.
You will find you will have a lot of nervous energy, especially on the first cruise, and will want to spend as much time on excursions, ship experiences, etc. Be sure to book your spa time on rhe first day on board, asap. The best times fill up quickly, and the last full day at sea is the best. This will give you time to relax, recharge your batteries, and unwind. Plus, you will find the best bargains toward the end of the cruise.