“Can I get you something to drink? Coffee? Tea?”

A coworker is visiting you at your home for the first time. You want to be polite, so you offer him something to drink:

Can I get you something to drink? Coffee? Tea?

Can I get you something to drink?

This is the polite way to offer a guest a drink when they're visiting you at your home. It sounds more polite than "Would you like something to drink?"

It's normal to offer people a drink when they visit you. You can offer food too, if you have something to offer.

Can I get you something to eat?

If you want to offer your guest some alcohol, you can ask:

Can I get you a drink?

The difference between "something to drink" and "a drink" is that "a drink" usually means alcohol, while "something to drink" can mean water, juice, coffee, etc.