Restroom/bathroom/toilet/loo/WC use and availability might be different than where you live:

In Urban Areas:
Major cities, modern malls, restaurants, and public buildings often have well-kept restrooms. Many of these facilities uphold high standards of cleanliness. Always take advantage of a restaurant or tourist location restroom when you can. There will be no fee to use. These restrooms will be stocked with toilet paper that you can flush and have a toilet seat.
On the Road:
For those venturing on road trips or exploring the countryside, gas stations often house clean and accessible restrooms. These establishments are prevalent along major highways. Additionally, many toll roads in Mexico offer clean rest areas with restroom facilities located at the toll booths. Bus stations often have restrooms, however your bathroom on the bus might be nicer.

Carry small change as some restrooms charge for use - 5 to 10p. There may be an attendant who provides a small amount of toilet paper. This practice is common and contributes to the upkeep of the facilities. It’s wise to have a toilet paper supply with you.
Local Business & Hotels:
In many older establishments, the plumbing is narrow and old and you can not flush your toilet paper. There will be a trash can next to the toilet for the toilet paper. At times there is no toilet seat, as these are not installed due to theft.

You will come to appreciate a clean modern equipped restroom. Use them whenever possible!