Thats how I got pulled in! 'Could you do the occasional night...' now I'm an ASL doing every week and odd weekends and camping trips and...
But honestly your in for a good time. The youngsters love the whole natural bushcraft (hehe) thing. This
back to basics is where the Scout movement needs to return as it seemed to migrate away from it without really knowing. Health and Safety started to play its part and a lack of knowledgeable volunteers didn't help either.
Get ready for a little paperwork as the CRB check will need to be done. You will probably need to have a meeting with the District Commissioner as well, purely a formality about what you have to offer the Scout movement and welcome you in. Then if you do the whole Assistant Scout Leader bit you will have to do your Child Protection Training, Health and Safety, and then some additional modules based upon your role. Have a look
here for more info.
Good luck and have fun.