The gameday plaza along Kirby Puckett place in the shadow of the dome will have your standard (IMO very blah) food options and (IMO ver very blah) entertainment. Trivia stands, merchandise trucks, restrooms (the one saving grace) and very limited beer options for sale for $7.50 a bottle.
I wish I had been over there the one home game we had this year (anger) so far to see if the food trucks were still over along 5th Street just a hundred yards or so on the downtown side of the Downtown East/Metrodome light rail station. Last season they had the trucks lined up. That would be a great place to check.
The plan was to get brewery trucks this sesaon but I don't think the city council got that through. So bring a backpack of beers but be wary of open container laws. You can have open container in the lot and on the plaza within the law. However, be careful other places even tho you will see locals walking around with open beers drinking away. The police generally overlook it but I would not do it if I were you.
Have a good time. I forgot it was a 7:30 pm game so that means the lot won't open until about 1. And you might think about pregame drinks and lunch at a place like Ike's or somewhere close to your hotel and walking down for some lot action after that