Wll, "gern" doesn't actually mean enjoy... enjoy is a verb while "gern" means something along the lines of "with pleasure".
So literally, the questions mean "What do you do with pleasure?" or "Do you live here with pleasure?" (God, that sounds absolutely ridiculous when translated literally, sorry.)
If you try to think of it that way, it is added at the end of the question, just like it would be in English.
Sorry, I am no grammar teacher but maybe this is a way for you to better remember / understand it.