check this
tutorial on how to easily post triggers.
btw, your triggers are working? D:
(Triggering unit) will refer to the unit which triggers the Event, in case of Unit Pick, it is the
unit beginning the construction, not the one being constructed. i believe Blood Mage is the unit that will be constructed. oh, and it's not Begins construction (as this is for structures), but Starts training for units. for Unit Time, you don't even have a unit in the Events, so it is useless to use (Triggering unit).
anyway, from what i understood from your problem, this is what you want:
a unit is selected from a training ground
the training ground trains the selected unit periodically while subtracting amount from the player's gold
..that?