I am trying to place the 3d cursor in the center of one of the faces of my object here but for some reason even if I select the face and use Shift + S then Cursor to Selected or Cursor to active it’s still not centering it. I need to add a circle there so I can cut a hole straight
The way Blender computes the center of a face depends on the pivot point setting:
If I am not mistaken, for any setting other than “Bounding Box”, it will compute the median point of the vertices you have selected and place the cursor there.
For “Bounding Box”, it places the cursor at the center of the bounding box of the selected vertices.
Edit: This makes no difference if your face consists only of 4 vertices and all angles are 90°, but if you subdivide one of the edges a couple of times, the median point will move towards that edge.
This is again because your topology does have n-gons… this sounds tedious but i would suggest to read the manual because you have a lot of question and even does make videos for them… this time could be spent better? Here https://docs.blender.org/manual/en/latest/editors/3dview/introduction.html are some essential hints for the Transform Orientations and Pivot Points.
Yes so LordoftheFleas has given you the right solution 
