Yooper Semi-formal, i.e. Semi-formal but if some plaid makes it's way in, that's cool. It may be a bit chilly in the ceremony area, but the reception will be warm. Dress accordingly. https://www.theknot.com/content/what-to-wear-semi-formal

Yes. It's also St. Patrick's day weekend, so there will be some Irish beverages available.

You can park across the street in the Historical Park lot.