Time for another well-abused homonym pair. I have no idea how often I see the phrase "roll model" posted online.
A roll, as a noun, is a small piece of bread.
As an adjective, it means some object which has been rolled up, or coiled, such as a roll of garden hose, or a roll of TP. As a verb, it means to turn over. Remember it this way: It has only one vowel, and it takes only one person to accomplish. You can roll a roll in butter, or roll up a roll of TP without any help.
A role is a part in a play, or a part you play in someone's life. We all need positive role models, people who are models that teach us how to play our role, our part in society. Ideally those role models will come from our family or church group, rather than from among the ranks of dysfunctional celebrities, but that's a post for another time. Remember it this way: this "role" has two vowels, just like you need two people; one to play the "role" and the other to be the audience.