As others have said a good place to start noodling around is either routines or smart lighting. Both allow you to set up conditional events using your devices.
To get to Routines, tap on the little checkmark icon at the bottom of the page in the mobile app.
To get to Smart lighting, tap on the Marketplace icon (the colored asterisk in the lower right of the mobile app page), then choose SmartApps, then āSmartThings recommends.ā
SmartThings has an official intro section in Support:
The following forum topic may also give you some ideas:
