Hi, I would love to get an option to change how much stone the recipe needs so I can change it how I want it. Because currently it says it would need 20 Stone for one landfill but the vanilla landfill only need 5 stone for one. Or could you guys tell me how I can change it in the mod itself?

There is no setting for it and I'm not planning on adding one sorry. I recommend installing this mod. It allows you to tweak recipes how ever you like.
https://mods.factorio.com/mod/recipe-tweaker

I'll take a look later if the standard cost should be changed.