what am I growing and when are they ready?

I got two pepper plants as seedlings from a coworker (I’m a teacher) who sprouted them with students, so all labels got lost. He thought they were the same but one has small leaves and produces many tiny peppers, and the other one has big leaves and exactly one (relatively) big pepper. What are they? Will the big one ever turn red or should I harvest it now?

Thanks for your help!