If you're turning on to Drove Lane from the A46 roundabout, take the second right turn. (The first is to Newark Golf Centre.)
If you look at the satellite view on Google Maps you'll see the second right opens up on to a large hard-standing area.
Head for the portacabin and get your pass from there.
The 'Blue gate' is the first left turn into the showground from that portacabin.
We have been located on a couple of different areas in the past, but both near that gate, to the left of the main drag as you drive in.
Do you know what day/time you'll be arriving? I should be there around lunchtime on the Friday, so if it's after then you should see my Carawagon on one of the pitches after you come through the gate. If not, the steward might have put up their Land Rover banner, though we rarely see the steward - we just sort ourselves out

See you there,
Robin.