Finding friends with the same mobile ability as my 6 year old son in Blackburn, Lancashire

My son has CP and his only barrier his his physical disability. He uses a rolator to walk as he is unable to do this independently. our concern as parents is that he is unable to keep up with his peers in mainstream school but also does not fit in with disability groups I have taken him to. There doesn't seem to be anything out there for children with just a physical disability.