Assuming your phone is on and online, you should be able to see its location on a map. From there, you can make it ring, lock it, set a lock screen note to tell whoever has it how to get it back to ...

If you have a Galaxy phone, you can also put unused apps to sleep. Go to Settings > Battery and device care > Battery > ...

Go to Settings > General settings > Automatic previews. It looks like it'll be tied to the Insights feature and becomes the ...