Yes, a misdemeanor will show up on your a criminal record unless you work out a plea deal with the prosecuting district attorney that includes wiping your record clean.

And yes, it is possible you could face harsher punishment because you are here on a visa. I don't mean "harsher" to mean a bigger fine or longer jail time, but rather they might not work with you as cooperatively on things like wiping your record and all because they don't like foreigners coming here and committing crimes. Also, I would imagine it is possible your visa could get revoked. I don't know though. If I were you I would find an experienced criminal lawyer in St. Paul, shell out a hundred bucks or so, and get the question answered that way. She or he is the only one that will have enough experience to truly answer your question.

And don't worry, lawyers (by U.S. law) cannot tell the police anything that their client tells them unless they tell them they are about to kill someone. It is called "attorney-client privilege." So feel free to tell whatever lawyer you ask that you smoke moderately or whatever as long as it is clear you are a client and are paying them (not just talking to them in a bar). Attorney client privilege kicks in when you actually become a client seeking legal advice from a lawyer.