OSM data base and markers

Hi guys,

I am a new OSM user. It is possible that such questions were already there, I could not find.
I decided to write an application (as part of learning programming), a small application that will display car mechanics, and after clicking on a marker, I will see the details. So far that’s it.

My questions:

  • OSM displays car mechanics but no markers for them. Do I have to have my own database or maybe I can add some markers for points that are already placed in OSM? Alternatively, can such a database be bought?
  • does OSM allow you to take any action when clicking on a given marker?

Thank you in advance.

Look towards the Overpass API.