See the below picture of a sample Ranked Choice Voting ballot from the state of Maine. All of the vendors competing for our county's business provide similar-looking Ranked Choice Voting ballots.
It's simple! You just fill in the ovals to rank your candidates in order of preference.
You can rank as many candidates as you wish, and your vote will only go to those candidates that you rank.
For another example, below is a Ranked Choice Voting ballot from the city of Santa Fe, New Mexico. The below is from the mayoral election held in March 2018.