I need help to do triggers for my map that i'm making

I need help to do triggers for my map that i'm making

OK how do you make like you know those circle of powers in risk how do i mkae thoes kind of things and so they will spawn units like every 30 seconds please i need to know how to do this please help me

the cirlces of powers can be found in the unit section under neutral passive in campaign and for the spawning make a action as
Time - Every 30.00 seconds of game time
Unit - Create 1 Footman for Player 1 (Red) at (Center of (Playable map area)) facing Default building facing degrees

thats just a example

You can find all that stuff easly if you try to find it harder.

-Rui

Thank you for telling me ^_^

anytime