need help with modding.just started out

so i made a new mod i made a new desicions category.but then i tried to make a new desicion in that category and i understand that i have to say what the desicion does but i dont know how i am supposed to do it . i want to make a desicion that makes all of your controlled states have 1000 construction slots.one that also sets the factory limit from 20 to 1000 .pls help

That is way too many slots for one decision, I suggest you break it up a bit.