exposure control

In my view, the best way is to use the File>Open in Camera Raw option.  This will bring up the Adobe Camera Raw editor (even for jpg files).  From there, you have a full range of sliders to edit exposure and contrast etc.

Otherwise, go to the Enhance>Adjust Lighting menu and use one of the tools available there:

Exposure is controlled by the camera.

If you wish enhance a picture, have a look under the "Enhance" menu in the Editor. esp. "Adjust Lighting."

If you are so inclined, post a representative picture here on the forum for more targeted guidance.