What to do if there is no gym or pokestop?

According to Niantic support page on Gyms and Pokestops:

Please note, we are currently not accepting submissions for new PokéStops or Gyms.

If you are having trouble finding PokéStops or Gyms near you, please try visiting a local park or other interesting or historical locations in your community.

It's possible that in the future they will accept new submissions for new PokéStops or Gyms, so you should stay tuned and follow any developments on this issue.

This article details a player who had success getting pokestops added by reporting it as a bug to Niantic support since there were Ingress portals but no pokestops.

Though slightly anecdotal, I have found the game client to be extremely buggy.

It frequently seems to stop updating data from the server, and will refuse to render Pokéstops or Gyms until it has been force-closed and relaunched.

It may be worth trying this.