when I edit my photo and save it in the application, it saves as a pp3 file and I can't seem to figure out how to change this. I have researched other apps to open the file, but I couldn't find a single one.
PP3 files are not actual image files but "processing profiles". When I was using RawTherapee one year ago when I got started in photography, I figured out that the
.pp3 files are rather files that contain the information of your edits in RawTherapee for each imported photo.
Technically, they are called sidecar files, and they are like the
.xmp files that other applications like Lightroom and Bridge use for the same purpose. See:
You can't disable the creation of these files - they are needed to store your edits.
If you find them annoying, you can either hide them from view in Windows Explorer or tell RawTherapee to put them in a central cache. See: https://rawpedia.rawtherapee.com/Sidecar_Files_-_Processing_Profiles#Storage
To export images, switch to the export tab of RawTherapee and select your desired image format (such as png or jpeg)