There's a big group of us going as far as I'm aware, no one will mind if you 'tag' along with any of us, it'll be nice to see some new faces! As far as I'm aware you don't need the £5 supplement and it's a free event. You will need your eventbrite ticket and AP though.
I probably won't get there till 6:30/7 so I might be a bit late, also SYNAW the park is being completely closed at 5pm so you'll be waiting around for like an hour for the whole park to open, but if you want I'll inbox you my number and I'll let you know where we are