Coming from Unity, you got to 'forget' a few things.
Plz read this first: https://www.scirra.com/manual/75/how-events-work
I changed some things in you capx.
https://www.dropbox.com/s/ybj6p5mf1tnee ... .capx?dl=0
If you have read that 'how events work' then i can introduce you to the 'picklist'. Do not read conditions as 'if this .. then that'. Read them as 'what do they add/remove from the 'picklist'.
If you look at my capx, to event nr 4. This reads as ...
Pick each instance obj_enemy one by one. The picklist contains now that one obj_enemy.
Add all instances of obj_waypoint's who's instance variable 'BelongsTo' is the same as the instance variable 'Owner' for the previous picked obj_enemy to the picklist. The picklist contains now that one obj_enemy instance + 4 obj_waypoint instances.
Pick from the previous picked obj_waypoint's the one instance with instance variable 'order' = zero. The picklist contains now one obj_enemy + 1 obj_waypoint
The action(s) now work only with those two instances of the two sprites in the picklist.
That is, in a nutshell, the base of C2.