Seven people are running, there are three open seats, you get to rank three, and your rankings matter. I find the counting process with ranked-choice ballots fairly intuitive for single-winner elections, but much more confusing for multi-winner elections. However, this video does a good job of explaining it:
The key things you need to know: you should definitely rank people in your order of preference, and don’t worry about “wasting” that top slot on a candidate you think will be broadly popular. Voting for a second and third candidate will not hurt your top candidate’s chances.
There are nine candidates; you get to vote for three, ranked, and your vote is allocated in this very complicated way that FairVote MN can explain to you. The important thing to know is that even though we have three slots and three candidates, ranking matters, and you should definitely put your favorites in your order of favorite-ness.