Is my chicken ill or is "she" actually a "he"?

[Nutrock]

Hi everyone,
Firstly, sorry if this is in the wrong section. I'm new on here and have been trying to find an answer to my question for about an hour but like I say I'm new so a bit slow here.
Anyways, moving on.
My mum and I bought 20 bantams for £10 at auction last month. All's well at the moment but recently I've noticed one of them is making a coughing/sneezing noise. We don't know wether they're hens or cockerels so I'm hoping it's just a cockerel trying to crow. Also another one keeps stretching its neck and letting out a little chirpy noise. Strange.
Hope someone can help and sorry for not giving much info, I'm not at a computer at the moment so can't upload pics.
I'll introduce myself as soon as I get home (from the allotment)
P.s- they've still got some fluffy feathers but I don't know how old they are. I think they're old English game birds but again, not sure. Look forward to learning about them.
Thanks, in advance.

 

[Happy Chooks]

The one stretching its neck and making the chirpy sound is a cockerel. I have a video on here of a 1 day old chick crowing. I can't find it from my phone, but you could search it.

As for the coughing/sneezing sounds - could be the bedding causing it, but I'd keep an eye on it. If they start having bubbly eyes or nasal discharge, that is not good.

 

[Nutrock]

Thanks Happy Chooks, I'll have a look for it.
As for the bedding, they just sleep on a ledge above the ground. They all huddle together along that. Do you think it could be the random weeds with random insects in them that we throw in there?