There are definitions of 3 accessibility levels on HAl site.
Ambulatory means you are able to walk so small thresholds should not be a problem for you, but there are some extr grab bars and such
Fully accessible means you are in wheel chair but able to transfer to another place and that there is adequate space and ramps, etc to get around you room and veranda. Bench in shower, roll in shower, etc.
There is a level in between and it means there is a right or left side transfer, not both.
It is pretty well documented on the site. The difficulty is getting the room that matches your needs.