Web App
To hide your sample Experiences settings either clicking on the Hide Sample Experiences button at the top of the screen above the main navigation bar to the right.
To show your sample Experiences again after turning them off, click on your avatar at the top right and click on settings. The Sample Experiences section will show this option.
Android and iOS Mobile
To either hide or make your sample experiences reappear, click on the three dots at the bottom of the screen and go to mobile. There you can change your sample Experience settings.