NPC Schedules

Could someone please explain to me how to make these schedules work:

It’s sort of explained here, but I don’t understand:

I really want to get SCHED_IDLE_WANDER to work on a group of NPCs so they’re in different positions for a series of pictures (assuming it does what I think it does).

Thank you.

That’s Lua coding you need there.

Could you please explain that to me? Or direct me to a place that can? or