I don’t really get what you mean:
How can you align a camera to a bunch of faces all pointing in different directions??
That’s impossible but do this (no real solution) if you meant just one face or some points:
- Select the camera
- Shift select the objekt
- go into edit mode and select three points of your face
- press Ctrl+P and parent the camera to the three vertices
- go into edit mode and select the camera
- press Alt+P and select “Clear parent and keep transform(Clear track)”
But as you can see that is just a solution to align to vertices.
if you want your camera aligned parallel, select it and rotate it 90 around its local axis and then move it as you want on its local axis.