The basic - and minimal - structure of a Map view looks like this:
You can add as many fields as you want inside the marker-popup, every field will be shown on a new line in the popup. The res_partner="id" refers to the field that holds the ID of the model "res.partner". If you have a custom model you'll need to have a link to the "res.partner" model, which is added in this definition.
If your Map view has at least two records this option will show all pointers on the map as routes with a counter inside of the pointer.
Defines in which order the Map view should show and sort the pointers. This will show all records as pointers on the Map view with a counter starting at 1. The "default_order" option takes an Odoo field on which the records will be ordered.