Hi, @markdarden53!
FossHub and GitHub are just two different websites where the Shotcut releases are being hosted. You can download them from either. It doesn’t make a difference.
Do make sure to also visit the Tutorials page which you can click to on the top of this page that has videos explaining how to use Shotcut.
Also, considering the main purpose you want to use Shotcut for, know that Shotcut has a feature called “Slideshow Generator” that can quickly create montages out of images and/or videos.
Here’s the page on how to use it: