Hello and a warm WELCOME to Sparkle and the community.
For the Gallery the solution is shown in the screenshot Woodrow postet. The key word ist “Slideshow”. You have to tick the checkbox and set the time.
I don’t think there’s any printware for Sparkle. What helped ma a lot (startet 15 month ago with Sparkle) was watching the Youtube Video Training Duncan published. Like this one:
It is from an older version, but the basics are more or less the same. Build a test project and fiddle around as much as you can. Upload it to a (non public) webspace and see the results.