Claiming Benefits after Living Abroad for Years

Hello,
Would really appreciate some benefit advice involving a family member.
My brother returned from New Zealand a little over a year ago to be closer to family after living and working there for 15 years.
He has suffered from an inner ear condition for many years, and it has deteriorated in the year he has been back.
He is now on a waiting list for an operation and hearing aid after being diagnosed with a hearing impairment “False Fundus.” Symptoms include - being hard of hearing (hearing loss greater than 35 decibels dB.), difficulty concentrating, extreme vertigo, nausea and frequent migraines.
He is a Joiner by trade - currently not able to work because of his health condition - and is trying to make a claim for ESA or universal credit.
He has to attend the job centre each week to do job searches even though he has a sick note each month from his GP to say he can't work. He explains this with each appointment, but still sees a work coach. He says he has not received any money after an initial phone call and job centre appointments over the past month, and does not seem sure if he will.
He has been back in the country for 14 months, so what is he entitled to?
Also, he and his partner have a 13 year old daughter diagnosed with autism who needs a lot of day-to-day support. Would they be entitled to Carer's Allowance or a child care payment?
Any advice appreciated.