What would you do if you were 20 and won just over $1mil?

I won just over $1mil in the lotto and I want to buy a house, I'm thinking a duplex so I can have my mates rent one while I live in the other. I'm still in Uni and working part time but I don't think it will be enough to retire on. I'm not great with money, a friend recommended this sub.

Also I'm in a relationship and made the mistake of telling my partner about the winnings. I don't want to get tired down, I would like to explore other options, we've been together for a couple of months only is there any chance they can take some of my winnings? How do I end it without losing any money, if possible?

What can I do to ensure I'm setting myself up for the future? Any advice is appreciated