Put "...or whatever" at the end of a sentence to show that you're not talking about only one specific thing. For example:
She's always asking for money for gas or whatever.
This means that this person asks for money for many things, including for gas.
Another phrase with a similar meaning is "...or something":
He said to get him a hamburger or something.
The difference is that "...or whatever" is more negative. You use it when you're talking about something that you don't like or don't think is important.