You’ll need a large indoor space, ideally a church/community hall or similar.
In the lead up to your event, ask people to bring cardboard boxes and tubes. Borrow golf balls and small clubs (you will need enough for one per team). You will also need lots of parcel tape and scissors.
Divide your group into pairs or threes, allocate them a space in the hall, and give them about an hour to design and build a section of the minigolf course.
When the time is up everyone can then have a go at playing the course.
You may like to award points to each team based on the design, execution and playability of their section of the course, and have a prize for the winning team. And don’t forget a prize for the person who gets the best score on the course too!