If my opponent has a facedown card in their staging area and some other stuff. i enhance with enraged golem which says to take the lowest control value printed on a foundation in my opponents staging area. what happens? do i get +0 damage cause it sees the blank foundation and such?

Yup, the printed control of a facedown card counts as 0 so Enraged Golem would give +0.

2.13.9.1 Any effects referencing a printed number on a face-down card would see that
number as a 0.

found it in the agr for further clarification. thanks for the answer though tag