What is a typical way for French people to offer something to a guest, and how might the guest respond?

For example, if a casual acquaintance is visiting your home and you want to offer them coffee, how would you say it?

And then, how might the guest respond?

This question comes from a friend of mine who speaks Spanish and now lives in Paris. Her question is that in Spanish (at least in Mexican Spanish), someone might say, 'Quieres una chelita?' or, 'Want a beer?', and the guest might say, 'Si hay!', or, 'If there is one!', as a light, gracious response. We would like to know if there is anything like this...colloquial, casual, slang, or otherwise...in French to offer things and then to respond.

Thanks for the help!