Hello and welcome,
Rural areas can be tricky to find POIs that may be eligible to be added to the Wayfarer map, but we do have a good thread that lists many POIs that one may want to look for: Tips for Rural Nominators
While I live in a city now, I grew up in a rural hometown, and have added many Wayspots there while visiting, with a good number of them being added to PoGo. I’m still looking out for POIs that could be added there, and have a few in mind the next time I’m there.
Also keep in mind that Wayfarer is the database map that all Scopely games, including PoGo, uses to determine game play locations, and there is criteria that has to be followed when nomination new Wayspots. Not all approved Wayspots make into the games, as they have their own density rules, with PoGo using S2 cells to determine game play locations.
Lastly, there is a test that is going on in rural parts of France, Italy, and Spain that has added stops/gyms to areas where game play would be safe to take place. Stops/gyms have been added to street corners and bus stops, which are currently ineligible per Wayfarer criteria, but if this is deemed to be a successful test, it could bring more game play locations to rural and low-density areas. More info can be found here: New Wayspots in Pokémon GO - Discussion