What advice would you give me for choosing between chicken breeds?

I'm planning on getting chickens later in the summer and I AM RESEARCHING LIKE A LITTLE CHICKEN GREMLIN, but I'm still unsure about what I want to do. I will be making a coop and run that are more than big enough to account for chicken math and making as big of a run as my yard can muster as our neighbors have cats that free-roam.

I was thinking about getting

all brahmas

all faverolles

or a mixture of chickens, I know I'd like to look into different breeds but I am unsure as I am a novice.

I know some breeds to stay away from and I know to stay away from roos until I'm more comfortable, what advice would you give me? I've been looking into breeds that are calm, docile, easy going, or chickens that just mind their business. These are going to be my pets, I'm not entirely worried about how productive they are but I think I'll probably change my mind after a little while. THOUGHTS????????