i know nothing of this

well i dont know triggers at all and i need help i am using blizzard maps to try and help me a bit but i am still lost :( i need to know how to place a trigger on a building what do i have to do o_O and it is a spawn trigger if that helps at all and i will be wrightin this stuff down so i dont have to ask a gain

I...didnt really understand that...at all... If you want to spawn units, you can use

Unit - Create 1 (your unit here) for Player 1 (Red) at (somewhere) facing Default building facing degrees

but, I dont really know what your talking about, so you'll have to give more specifics.

Look over the triggers existing in a tower defense map. Those are generally the easiest place to start.