Question: I am currently one a b1 visa and have met someone and would like to get married. i am from Canada, would we be able to file for my K1 while I am in the US or would I need to return to Canada to file, I know that I need to do my interview in Canada eventually but I am hoping that I can stay here until that point?

Answer: you cannot get K visa in the US.  You will have to go to the US consulate to apply for K visa after CIS approves the K-1 petition).  It will take about 4-5 months and in the meantime you may stay in the US if you are permitted by CBP to stay here(under B visa or under VWP).