“You want me to hook 'em up for you?”
Your aunt just got new speakers for her computer. She hasn't opened the box or started using them yet. You offer to connect them for her because you know that she's not very good at figuring out technology.
You want me to hook 'em up for you?
This is a way to offer to do something in a casual and cool way. Of course, the more grammatically correct way to ask is using "do":
Do you want me to pick you up something?
And an even more polite, more formal version is this:
Would you like me to pick you up something?
This means to connect electronics so they work correctly. You might "hook up" your camera to a large display screen, or your smart watch with your smart phone:
I bought it last week but I don't know how to hook it up.
It’s also possible to say hook up (something.)
I need the right cable to hook the speakers up with the TV.
This is “them,” but in speaking we often drop the “th” sound, especially when “them” is not very important for the meaning of the sentence. “‘Em” is usually spoken quickly, and blends together with the word before it.
Give ‘em five more days.
This is something you can say to a sports team that you're cheering for before the game:
Go get 'em!