Autistic son and esa

Hi there i am just looking for a bit of advice.. i have a 18yr old son who has autism he was previously enrolled on a computer science course at collage but very quickly realised he could not cope in that environment and had to leave due to the amout of disstress it was causing him....now that he is no longer in education my child elememt and dissability elememt of my uc has been stopped so my son would need to claim his own benifits....he already recieves enhanced care and mobility from pip and i have been aproved as his appointee as he cannot manage his own money.
My question is what benifit does he qualify for?..would it be universal credit or esa?....its all so comfusing to me any help would be great thankyou for reading.

Thankyou david for your reply do i have to apply for the lcwra or will it automatically be added to his uc as he is getting pip?....my son did not have to go for a face to face asseament for his pip as it was paper based because of the amount of supporting evidence i had sent with the claim form it was not deemed neccessary.