Hello and Welcome To BYC! Cute chicks, you can post pictures in the What Breed Or Gender Is This forum for help with figuring out what they are https://www.backyardchickens.com/f/15/what-breed-or-gender-is-this would guess a Barred Rock and the two brown ones Easter Eggers from the feather puffs on their faces.
Definitely looks like a Barred Rock up front, but not sure about the babies. Stop by the What Breed section for more help. Kelsie has left you with the link.
Welcome to BYC! I agree with the other members. You have a Barred Rock (the big one) and two Easter Eggers. The EEs are my granddaughter's favorite chickens. She loves the different colored eggs they lay. Good luck with your flock.