@Rosa2892 Yes, you should definitely describe the 4 plex situation. Guests need to be clear on whether there are other tenants in the building. Also, I didn't notice if you did, but if there is a shared hallway or yard with other guests or tenants, that needs to be mentioned as well.
Yes, there are plenty of Airbnb guests looking for long term, so you will likely get plenty of interest, just be aware that you won't have the same protections you would with a standard lease situation.
I would also steer clear of accepting guests with no history of good reviews on Airbnb. There are tons of newbie guests these days who have no clue how to be a welcome guest. That's not such an issue if they are only staying for a night or a few, but you don't want to get stuck with an objectionable long-termer.
Make sure when you communicate with guests when they request a booking, that they have thoroughly read through all the listing information, are aware of the house rules, and agree to them. Lots of Airbnb guests, especially new ones, do not read through hardly anything- they look at the pretty photos and the price and have the typical reading attention span of the texting generation.