Before you do anything you need to check that the property is listed as a horse property with the county or city. A 75 X 100 lot is not a lot of room for a horse or horses and I would expect the property to be listed as residention, not agricultural.
If it is ok to do, then likely there'll be some permitting issues and code issues you need to resolve first.
If I was renting such a place for a vacation, I'd want some kind of shelter for the the horses (mare motel or loafing sheds), hot wire around the fencing to keep horses off would be ok. I'd like a list of local restaurants, grocery stores, vets, farriers and a trail map. I would want to know that the stock tanks and stalls or shelters were cleaned thoroughly and disinfected between each guest. You would need to require Coggins & Health Certs, and I'd want documentation of a horses Rhino vaccine within 60 days prior to arrival at the place. Rhino or EHV-1 is a thing that's spread through shared water very commonly.
The house(s) could be rustic, so long as they were IMMACULATE, white glove inspection clean. Hot tub would be nice, some kind of TV would be great, even a collection of things to put in the DVD or whatever. I'm pretty finicky, so wouldn't care about provided meals, I prefer to do my own, though it's a service you could offer if you wanted to. I have no idea about what you could charge, I'd check with local rental agencies and hotels and try to figure out something that would make your place more affordable or attractive to the guests.
Oh, almost forgot, you'll need liability insurance, releases of liability from each guest and signage around the property. https://www.mysafetysign.com/arizona...IaAnEAEALw_wcB