Assisted living and nursing homes often have very different room formats. Assisted living facilities tend to offer studio, one and two bedroom apartments. Some apartments will come furnished and others are up to the resident to fill with whatever they wish. Most of them will have larger bathrooms that allow an easy transition into the shower and through the door in case you have a walker or wheelchair. The one thing that is often difficult to find in these places is storage space. Most places have very little closet space and that is often an adjustment.
Another aspect of senior living that can differ by facility is the kitchen. My mom was in a facility that had a kitchen but with no active appliances with the exception of a refrigerator. There was no microwave either so that was something we had to adjust to. There was an oven but it was disconnected. There are also rules about having toasters and coffee pots in some places. Usually this is due to safety concerns. Make sure that whatever you are looking for you check into what type of kitchen is offered and what appliances are allowed.
One final thing to consider is the flooring. Many newer facilities are putting hard flooring in their apartments so that people are able to move more freely with well chairs and walkers. My mom's place had all carpeting which was difficult for her. We were told we would have to pay if we wanted to switch the flooring in the unit. These days you will probably see units with hard flooring or a little of both. Always ask what options you have based on your needs and wants.