There really isn't enough information to help you here. We can assume you're on 1.13, otherwise mcedit not being updated wouldn't matter, and that you have built an iron farm you watched a tutorial for but we still don't know if this is pure vanilla SSP or modded SMP where something beyond normal game mechanics could be effecting things. You've told us that the farm is built on y=9 and there is a wheat farm about 30 blocks away (no clue why either of those would matter) but you haven't provided any screenshots of the area in question so we can see if anything around the farm could be throwing the golem spawning off and we can see the farm was built properly. It would also be good to know if this is java or bedrock since I've heard many reports of weird spawning behavior of different mobs in bedrock due to too many mobs in the world.


It is easier for people to help you if you provide us with as much information as possible. Just saying you tried to build an iron farm and it doesn't work isn't giving us much to work with.