I used to have the free app - Adobe Reader. I no longer have it. Don't know why. I have instead, PDF Pro and did not knowingly purchase it. I want it removed and purchase PDF Lite.

Yes, that's kind of a catch on Adobe's site. You click on the Reader link, but on the download page you have to be careful to select the Reader at the top, and not the Pro trial below that. Worse, if you click the trial, it starts a download and install of the Pro version immediately.

To remove the Pro version, open the /Applications/Utilities/Adobe Installers folder. Similar to what's in mine below, you should see an uninstaller for Acrobat Pro. Run the uninstaller.

If you've already been signed up for the monthly fees, make sure to contact Adobe to cancel any such subscription.

https://helpx.adobe.com/manage-account/using/cancel-subscription.html

Then go back to the Reader download page (as already linked to by BDAqua) and make sure to choose the free Reader.

Wondering, did you hit the 7-day free trial maybe???

https://get.adobe.com/reader/oad | Free PDF viehttps://get.adobe.com/reader/oad

Check...

See your purchase history for the App Store, iTunes Store, and more - Apple Supportore, iTunes Store, and more - Apple Support

If you think you paid for it...

Request a refund for apps or content that you bought from Apple - Apple Supportt you bought from Apple - Apple Support

You're welcome. 🙂