New to LR's

Hello all, recently purchased a discovery 3 from ongar bridge Land Rover in Essex, I live nearby and am looking for somewhere to take it off road, obviously I'm new to it all so don't want to take it anywhere too challenging to begin with, I need to start somewhere though. I've heard there are a few green lanes around here, on the a414 near Chelmsford and also in fifield. Is there anyone on here close that could give me a few pointers are show me some places to go.
Thanks in advance
Will