Creating Points in Google Maps api with data using PHP / MySQL [closed]

I'm trying to learn how to tinker and make maps using google maps API but I want to know if I have and how to do a map automatically using points (coordinates) that were registered in the database through a form. And if these points are repeated as putting a single point on the map with the total points in the same coordinate in the appearing infowindow.

I want to do something like the example below:

link

Thank you very much