Translation:I met Teacher Wang this year.
Well, the English sentence is grammatically incorrect. Firstly it would be, "This year I met teacher Wang." because we've specified a specific time "this year." so no auxiliary. Secondly, it is more natural to say, "I met teacher Wang this year." In English, you just put details at the end.
This is irrelevant to the translation for learning purposes. Calling one's teacher "Teacher X" is not wrong whether or not it is weird from one's personal experience. Without context, Teacher Wang is more informative than Mr. wang. And finally, 老师 is not an acceptable translation for Mr.