New to Forums- Confused about what breed I've got

hi all, i'm new to the forums. First off, I want to say WOW!! what a wealth of info here.

Not only am I new to the forums, I'm new to keeping chickens. I got my first few yesterday. I bought them from a gentleman that sells them on a corner I pass daily on the way to/from work for the last few years. He showed me his state license and the chickens have been vaccinated for Coccidus(?) - not sure of how to say/spell it- and they all appear to be active and healthy. They hatched on Feb. 19. Three of the five have been de-beaked.

I am curious about what kind of chickens I got. He said that the 3 white ones were 'white something or other leghorns' and the 2 blacks were 'bantys'. They both lay brown eggs. Now, I asked a ton of questions on how to house and care for them and I guess it was a combination of information overload and lack of ANY kind of knowledge about chickens because much of what I have read here and the photos i've seen seem to contradict some of what he said.

The white chickens are just that- solid white.
The black chickens are black with white speckles.
Both have normal 'flesh' colored legs.
Both are layers.
Both lay brown eggs. (which i thought that i read that White Leghorns lay white eggs?)

I also seem to be getting the impression that the term 'banty' encompasses more than one particular chicken?

Another question I have is in regards to the dyed chicks that I have seen at the local feed supply store. Aside from the fact that I do not support the dyeing of any animal, I am considering picking up a few. My reasoning is that the ones I take will definitely live a good life as compared to being picked up for novelty Easter gifts and likely living a short life in a cardboard box.
Is there any typical type of chicken used for this Easter dyeing thing? The feed store employees did not seem to know what type they were. I also understand that I could end up with Roosters instead of chickens and wonder how many roosters can be kept together. Will they fight?

I can attempt photos of my birds this afternoon and get them posted, I know that will help. I also plan to stop and speak with the gentleman I purchased the birds from. I just like to arm myself with as much knowledge as possible, and there appears to be an unending supply of it here!

Thanks in advance for any replies. Hopefully, I'll graduate out of the Newbie class soon.