I won't be in the area, but you are in for a good day out.
Warped are a very well known company in UK paintball. They also run the UKs largest paintball game over a weekend.
A little advice - getting hit by paintballs does hurt, but only for a moment.
If you sit at the back hiding you will find it hurts more when you get hit. Take a moment to run around like an idiot and get the adrenaline running and you will feel nothing.
Everything that is essential will be supplied, but I recommend wearing fingerless gloves.
Wear comfortable clothing in layers. You will be supplied with overalls but they won't provide any padding. Something like a t-shirt and a sweatshirt will give you plenty of protection under the overalls. A little scarf is handy to protect your neck. Good footwear is essential. High heels look good but are not ideal for running in the woods.
Spare clean clothes are essential for the journey home, and some wet wipes will always come in handy for a freshen up.
As shown in the prices expect to use 500 paintballs if you like to sneak around, but allow for 1,000 for a good shootout. You will often see tickets being sold at £10 for a days paintball but then people get a shock when they use all their 'free' paint in the first game. Rockcpluk have wisely shown the realistic cost. If you want a little more paint on the day then get together with others and buy about 1000 at a time - that way you will get the best cost.