first child benefit, on DL how long will it take?

[chorc123]

Could anybody advice me that, how long does it take first child benefit come through, at least a letter of approval with child benefit number?
We are on DL and in position to apply for ILR. We went to CAB, and were told to just fill in a form and send it back. I have NI number since many years ago but my partner hasn't got it yet. I am unemployed due to shop closure and my partner is on low income. I have filled JSA form, I still haven't heard anything yet.
We went to council today and apply for housing and council tax benefit, we need to provide 2 form of proof, my partner could only provide his passport and nothing else, as all bills are not in his name, then he was asked for Child benefit number, we couldn't give as we still waiting to hear. Because of we are on low income at the moment, we couldn't pay our rent for few weeks, so we are very desparate to know what we can do.
Does anybody has any similar experience? We don't even able open bank account, as we couldn't even able to provide enough 'proof' of ID and address.