I got mail? Hmm I not to sure!

There are post offices. You can get a box if there is one available, or have things sent to general delivery. There is no home delivery. Most people use Mailboxes Etc. or similar service. Even that can take a week or two.  Water and electric bills are hand delivered and stuck in your gate or front door. There aren't addresses as we know them either. You'll see in (neighborhood) behind Romeros supermarket next to the travel agent on the corner, for example, as an address.

I maintain a US address (my daughter's house). If there is something I need to see she can snap a photo and send it to me. It is very rare that she has to physically send me anything.

This will definitely put a damper on any ebay or amazon shopping habits! Of course you can buy things but you have to pay shipping and sometimes customs, and wait for your item to make it here. For mail within country, there are currier services that deliver mail and packages between cities.