Welcome Kev,
i live between WGC and Hertford and been around Broxbourne woods alot last year , not so much this year due to the weather and bike problems.
but there are some nice tracks there which a complete novice can do to learn about the joys of mud. one word of warning you can hear the Lions from the Zoo in there which i learnt on a night ride in there , ive never pedaled so hard and fast in my life
as Mooh said its a bit of Nettle/bramble fest on the out the way single track.
once my rear brake decides to free it self i be happy to have a ride there with you or anyone else...
Steve