How did you enjoy (something)?

"How did you enjoy ___?" means "Did you enjoy ___?" You answer by describing your opinion of that thing.

For example:

How did you enjoy the massage?

How did you enjoy your trip?

People often ask "How did you enjoy ___?" to someone who they're not very close with. It's not a very personal-sounding question. If you know someone better, you ask "How was ___?":

How was your first day at the new job?

Mr. (last name)

"Mr." is a title that you use before someone's last name to show respect. It can also be written "Mister".

For a complete explanation of when to use titles like "Mr.", read this article.

your stay (at a hotel)

Hotel employees use the phrase "your stay" to talk about the time that you spent there. For example, they say things like:

Please enjoy your stay. 

How was your stay?

If there's anything I can do to make your stay more enjoyable, please don't hesitate to ask.