my advice, purley on the mistakes I made are try before you buy and dont rush. lots of people will tell you to buy such and such or this over that...what suits you best??
firstly, get talking to everyone, dont hide, be there and chat, ask questions,make friends
then personally. Id buy a cheap nasty mask first, this way you can do things like go to chrono areas and try guns etc etc
ask to try everything, worst people can say is no, the majority of paintballers are nice and pleaseant people and will for the most part let you try their gun over the chrono etc...as long as they are nearby, no one is gunna let you wander of with a grands worth of marker..so dont be suprised. also people are less likley to say no to you if they have seen you about before...see point 1
Watch listen and learn. which guns break down more, what masks look uncomfortable, what works, what are most people shooting and why?
after you have had the time to look at things, then buy some gear.
worst thing you can do is go into a shop spend 300quid blind come away. play a game and find out its awful
my two pence