Ok, I’m working on my own time to create a game, and exploring technical possibilities on this adventure !
In the beginning I was planning to do the map 2D plain, the coordinates 10,10 would be easy to calculate, was just a matter of multiply the x,y by the width and height of the small tile that would be in the screen.
But nothing is simple ! My daughters are helping me on the discussions of the game, and also helped to create the map, thanks girls you are the best daughters !! The 8 years old one come with the great idea ! Hey dad, why don’t you make the game like the age of empires or warcraft III maps ? a little bit shifted back … Oh well that began all of this 
Now I have a new map to work with
And the nice problem of how to convert from a screen coordinate to the map coordinates ? remember that in this case the screen 0,0 is the top left point of the window.