Want to do a solo cruise, but I've never traveled solo before. Advice?

I (30F) recently got back from a 6 night Royal Carribean cruise on Oasis of the Seas. It was definitely the best trip I've ever taken. I loved being on the ocean and going off the ship to visit the ports and doing excursions. Oasis of the Seas also has my favorite musical on board, so going on a cruise also means getting to see my favorite show which is a HUGE bonus for me.

Long story short, I'm itching to get back on the boat. There's a cruise in July that I'm looking at doing. My issue is I've never traveled solo before. This last trip was with my sister and her partner. While we had a blast, the two financially cannot come with me on this trip. I really don't have anyone who could come along, so if I did decide to go, it'd be solo.

I'm not concerned for when I'm on the boat, I did a lot of stuff on my last trip by myself and had a great time. I'm mostly worried about the actual traveling down there and back, and getting off the ports. This cruise stops in Cozumel and Puerto Costa Maya in Mexico. I've also read that Royal Carribean in general aren't too nice to solo travelers. Do any solo cruisers, specifically women, have any travel tips?