Hi mds 101, If thinking on coming on one of the rides, just let the group secretary know you coming so that they wait for you if you bit late getting to the start and yes can also turn up at the start has well. No you don't any special skills for riding off-road just come on a bike you are comfortable on this can touring bike or hybrid bike or mountain bike, you should be able to ride about 25 miles or more in day and also bring pack lunch.