Hi,
I don't know what your particular situation is, but I can say that cruises are probably the most accommodating types of vacations for those with disabilities, especially if one is in a wheelchair. If you have a motorized chair, it must have a gel type battery, which almost all have today. Request an accessible cabin. They may cost a little more, but they are roomier, have wide doors, roll in showers and closets, etc. Most cruise ships have accessible cabins for all types of rooms: inside cabins, outside cabins, suites, etc. Almost everywhere on the ship is accessible for a wheelchair.
The problems come in away from the ship. Some ports are not able to accommodate the larger ships, and they must anchor in the harbor and use tender boats to bring passengers on shore. The last time I was on a cruise, these boats could not handle motorized wheelchairs. Also, most shore excursions are not wheelchair accessible.
You will have priority boarding, so you will be able to get on the ship before everyone else. This is an advantage because you can grab a good spot to wait until the rooms are ready. Overall, you should find the shipboard experience very nice. In ports of call, maybe not.
Hope this helps