not sure of any in surrey but i just did my first one and it was great - just try not to worry too much dont put too much pressure on yourself and remember its for FUN! lots of local shows have beginners classes at jumping and everyone seems really friendly. google riding diary and that will take you to a link where they are all listed. good luck!
We have one on the 16th September- its a christmas party with music, fancy dress, games and show jumping starting at 1 foot.
Schedule is on here: www.hall-place.com