Yes you need to be there early or as I said you will have no stand as it is not allocated by edition staff. Edition is just turn up and figure it out unlike the other shows where you have to organise a plot before the show and get people committed which hard work!
Who you contact, no one really, start a thread on here to get some people to commit to Sunday or both days (Sunday main day) and then find out if any moderators are going or arrange for someone near a mod at a meet or whatever to collect the banners and flags. As I said camping and having a beer and BBQ is what the show is all about really IMO. Or you don't really get to meet people as they just spend all day looking round the cars,stands and stalls all day and the stand becomes a car park.
It's so cheap to camp for 2 night or one (but camping Sat night is best as all the good spots are gone and you end up miles for the loos/showers/show!).
This will be my third year and each year I end up doing more shows lol