XX621 (now G-CBEF I perceive...)
There are three sorts of adult volunteers who assist the ATC:
Civilian Instructors (CIs), Adult SNCOs and VR(T) Officers.
One of the essential differences is that uniformed staff are paid (up to 28 days per year), while CIs are not. As a
quid pro quo uniformed staff have a (fairly gentle) minimum monthly commitment of 12 hours.
I'll try and link to soem useful web addresses for you, or if you PM me with your location, I could give you contact details for your nearest ATC Wing HQ (there are 36 in the UK), which might be a better starting point than a squadron, if nothing else they are manned by permanent staff...
Edited to add: try the Air Cadet Website
here and follow the "Adult Recruitment" link.
Note to Mods - this concerns recruitment of volunteers and is not commercial