Being that this is your first cruise I would stick with the room that you have booked. If you really enjoy the cruise, and I'm sure you will, you may want to upgrade to a balcony next time.
It also really all depends on your preferences too. If you plan on doing a lot of activities and spending very little time in your room then the cheapest cabin is the best way to go.
If you are like me and love just relaxing and looking out at the ocean, then a balcony is preferable.
Whatever you choose, have fun with it!