We've got chickens, can highly recommend it
The Rhode Island Reds are the quietest IME, the Black rocks are lovely but do make a bit of noise.
There's quite a bit of info on google about keeping them, the run you have is plenty large enough for half a dozen although the guidelines probably recommend you could keep a lot more than that.
They do like being let out, but they will peck at any plants or any greenery. They do a great job digging the veggy patch over in the Autumn/Winter too
We rarely let ours out during the growing season but will occasionally when the Daughter is employed on veggy plot guarding and "shooing" duties
They've got quite strong characters as well, surprisingly. We've got rather attached to ours
You'll be amazed at how good a proper free range chicken looks as well. Ours are now huge, glossy cat scaring buggers
BTW, they supposed to stop laying when the days shorten. I forget what the trigger is but I believe its when there's less than 14 hours of daylight (google will reveal all.)
You get round it by supplying artificial lighting, it doesn't have to be bright.
Saying that, we've stopped doing that as it seemed unatural, our chickens continue to lay but at about half the rate we get during the longer days.