Yay! Welcome to BYC and the wonderful world of chicken keeping!

This is a great forum...a flock of friendly folks with tons of great stories, recommendations, support, and ideas.
I think you have a few Easter Eggers there...they look like females. Since they were purchased this spring, they're near point of lay! (Roosters will have pointy saddle feathers and curving tail feathers.) That means you'll get a few colorful eggs soon! Easter Eggers can lay green, pink, cream, brown... it'll be a fun surprise!
Chickens are easy and do well transitioning feed. Blend what you have left over of their past feed with the new feed you want to switch to. Dried worms for treats are great (my chickens go crazy for their mealworms, and it's great protein for them).
They love their dust baths, so they'll dig little potholes to bathe in...plain ol dirt is perfect.
You're set up well and doing your homework

enjoy your lovely chickens! You'll love 'em!