Is there a way to take a folder untitled and containing 135 jpg files and select them all to get them to display in a slideshow so I don't have to click each one to move to the next jpeg

See the following Apple Support article for information on creating a slideshow: Create slideshows in Photos on Mac - Apple Support

I would use PowerPoint and use Menu > Insert > Photo Album then select the folder containing the images I wanted included. Each image will be placed on its own slide. Then create a slideshow in PowerPoint with the timing/captions that you want to each slide to be shown automatically.

If you use Option+Spacebar QuickLook, it will show them all as a slideshow. No configuration options like with making a real slideshow in Photos or iMovie, but if you just want to turn on a quick slideshow, it works pretty well.

You can select the first image file in the list and hit the spacebar to bring up Quicklook. Then use the forward and back arrow keys to navigate thru the list of image files.

kimfrombartlett wrote:

so I take it i have to move the folder into my photos app before making them into a slide show

Either that or into Keynote or a 3rd party slideshow app like the free Photostage app. 

The free slideshow app, Photostage, is a lot like iMovie 6 HD which was IMO the best iMovie version ever offered as it allows multiple audio tracks as well as individual transitions and slide timing.

It has a bit of a learning curve but after you get what you want you can save it as a movie file. I used iMovie 6 HD a lot so when I found Photostage it was a win-win for me.