I have to disagree with some of
@Edward T. 's corrections.
I would
always say "to my house" not "to my home". Could be a UK/US difference, I don't know.
I would never say "at that time" except when talking about a state that lasted for a long period e.g. "At that time, I was working as a journalist" not "At that time, I was playing tennis" (unless I want to emphasise that tennis was my hobby then but I don't do it any longer, but it still sounds weird to me - I would say "I used to play tennis").
I think it's fine to end a sentence with "then". To me "I was playing tennis then" sounds much better than "I was playing tennis at that time".
These are all pretty minor points though. I think you have definitely understood the basics of using this tense.