How do I go back to the pictures original settings?

Laura,

Just click on any history state below the top one, and your image will revert to where it was before.  For example, let's say you first cropped your image, then adjusted exposure, then adjusted saturation, then adjusted clarity.   Your history list would look like:

Clarity adj

Saturation adj

Exposure adj

Crop

Import

Click Import and your image will revert to the original state -- no edits.  Click Exposure adj and the image will be cropped with exposure change,  but no change to saturation or clarity.  You can experiment and click any state and see where you are.  However, if you click a state and then do an edit, all previous states above will be lost.  In other words,  if you click Exposure (in my example) and then make a Fill adjustment, the Saturation and Clarity adjustments will be lost.  Of course you can do those again if you like.

John