Hi Chloe
if you want to dod some biking and keep yourself to yourself for a while, i would recommend going into the woods to the left going away from epping towards Theydon bois, there are a couple of hills, some fast bits and some grassy muddy bits, you could do a couple of laps there to suss out if your bike will be up to any tougher stuff.
alternatively ride up to high beech and you will find lots of roads there, you can ride along the roads and dip into the woods every now and again without getting too lost.
its very muddy at the moment so be prepared to get dirty