User Input

I cannot figure this stuff out, and I would really appreciate help (please pretend I'm about 8 years old-I'm not, but this I'm having a hard time understanding this stuff).

I'm trying to figure out the "sixteen ballerinas" world:
-How do I allow a user to input a name? (as the name implies there are16 ballerinas and they all have different names).
-How do I get Alice to go through each name, and:
-if you enter a ballerinas name, that ballerina responds with an action?
-if you enter a name that doesn't belong to a ballerina, one of the ballerina responds by telling you there is no such person?
Thanks!