Simple pathfinding

hi guys,
i am so stuck

My goal:
Click a red actor/tile (either 1 or two 2) and the green actor will go there on the tile based path.
How do i achieve it?



I ran tests where the actor checks if there is a tile next to it and that works (walking the path) but i dont know how to do it with mouse click.

You could try using Merrek's AI pathfinding tools and a behavior that makes an actor follow a path.