check out
With or without an object
Leave a hotel after paying the bill
They checked out early on Sunday.
Look at or investigate (informal)
Check out this video!
With or without an object
It can be used with no object, and it can also take one. With an object it is usually separable: turn the volume up, turn it up.
Practise it
Add it to your daily practice or see every verb with up.
Further reading: check out on Wiktionary (CC BY-SA).