Slideshows in random order

Incredible or not, Apple has not provided a randomization feature in the Photos slideshow playback feature. (Some users here have complained about getting unexpected creation order, but that's an entirely different question.)

If you want your needs and wants to be noticed by Apple officially, and considered in their future planning, you can use their official feedback path:

Feedback - Photos - Apple

Don't expect any direct response, but we are told that Apple staff review and record submissions made through that path and forward relevant information to planners. Some suggestions do eventually see the light of day, reportedly.

I'm not 100% sure what you're asking here.

If you're saying you don't know how to arrange the slides in a slideshow in a random order, I'm afraid there's no way I can think of (without resorting to some esoteric AppleScripts).

The best you can do is arrange the slides yourself. When creating the slideshow you'll come to a screen that allows you to play the slideshow full screen, or preview it. If you preview it, you can see thumbnails of all the slides along the bottom. You can simply click and drag slides to wherever you want in this bar.

You can, however, post your question in the Photos Community, and it's possible one of the stars there will have a way to do this. Photos Community Discussion Forum