How to get screensavers on iPad?

iPad isn’t like a desktop or laptop computer - where the screen switches to a “screensaver” when the computer is idle. iPad will Sleep when idle, shutting down the screen to save power - defeating the entire purpose of a screen saver. 

You can, however, set a Wallpaper for your Lock and Home Screens from iPad settings:

Settings > Wallpaper > Choose a New Wallpaper

You might choose to have your Lock Screen wallpaper change automatically, or to display different pictures from your photo library using the photo shuffle feature:

Change the wallpaper on iPad - Apple Support

Ipads do not have a native screensaver app.

If you'd like, you can give a try to this 3rd party free app:--> https://apps.apple.com/us/app/flurry-screensaver/id991374400

Regards

Giulio