Once I have entered text onto a photo, how do I exit and go to the next photo in my slide show, using Elements 2018? Right now I have to save,exit the program and restart. Not very intuitive.
By Elements 2018, do you mean Premiere Elements 2018, Photoshop Elements 2018 or the Organizer?
There are several ways to make a slideshow, and both Premiere Elements and the Organizer have slideshow creator tools.
From your description it's not clear which tool you are using. Can you be more specific about how you're entering "text onto a photo"?
I am using the Video Editor. I inserted a photo of my kitten, clicked TEXT (top bar), NEW TEXT, DEFAULT TEXT, and a box appeared that allowed me to enter my text. When I finished, I can't find anyway to get back to the next photo or anything else for that matter. I am locked in the text only mode.
Click on any blank space in the timeline.