DO i need a passport?
Please reference this site for more information and pay attention to disclaimers: https://www.royalcaribbean.com/faq/questions/united-states-citizen-travel-documentation
I want a cabin for one. can i have a cabin for one?
You can have a cabin for one, but you're going to have to pay for a cabin for two. All prices are based on double occupancy in each cabin.
I don't know who i am going to travel with yet. should i wait?
That's fine. Just book the cabin know you will have to pay for two if you don't find that roomie. You can add a name up until right before sailing.