The stairs are standard wood stairs and the wood is stained from food traffic.

On the outside it looks like it needs new siding because it has stains and dents on it.

If the wood trim has a decent wood grain pattern, strip and re-stain in a shade that co-ordinates with other wood (stair banisters, wood floors, etc) in the house.

It may end up being painted or stained concrete).A combination of the Allure flooring and good tenant screening should give you many years of service life.

Stain the pergola in a rust.These simple, inexpensive improvements will so completely transform the building you won't recognize it, and will attract much better tenants.

stain master luxery vinyl is vinyl.  

If I want to remove the mold staining after the mold has been killed, I use Zep Mold and Mildew Remover.

I would check the roof, attic space if any (look for stained boards or trusses which could indicate a previous or current leak) and a check under the house crawl space if possible for rotted joists or wiring hanging down or anything else that looks out f the ordinary.

The woodwork was a MESS and I saw a good 20-30 hours of sanding and staining in my future.

@David Wolf What's the big ugly stain on the back of the building?