Walkons
If you have your own gear, Walkons are a good place to start, you turn up at the site, make up teams with the other players and go off and play in he woods for the day, no pressure, its all about fun, plus the guys are nearly allways friendly and a good source of advice if you ask around (though as always, a few opinions will be needed to be taken with a pinch of salt
).
If you want to play pure rec ball with site equipment you won't have to lay out on your own gear, but it will cost about double each time you go!
If you've never played at all, a rec day at your local site is the best way to see if its for you though.
Typically a walkon will cost around £50 for the day including site/green fees CO2/Air fills and a box of site paint, lunch may even be included! A very few sites will let you rent equipment, for a few quid more, though do check first, don't assume! Some sites may be willing to lend packs/pots or even air/CO2 tanks if you are short, but again check first. Walkons tend to be organised by independent sites, including some Skirmish sites, if you're in the south 2 I can reccomend are Skirmish High Wycombe 2nd Sunday of each month -
link, and Holmbushe (near Crawley/Gatwick), 3rd Sunday of each month -
link. For other locations ask around on the forum.
If you are thinking of getting your own stuff ask around here to see what people suggest, personally I would start with a well fitting & comfortable pair of goggles, then look for a marker - a proven low price electronic one like an Ion or Promaster or similar, rather than a tippman or SP8, while I have notheing against either of the latter a good starter electro will be just as good in the woods and if you want to try tournaments you won't need to beg steal or borrow another, and an air supply, hopper and pack for your spare pots, a set up like this can be got for £200 - £300 (probably the difference between 4/5 punter days and a 6 months worth of walkons!). You can start playing in baggy jeans or combats and an old football/rugby or sweat shirt and pick up other stuff along the way.
Most important, play at an organised site, you'll gain much more, and remember you can't just go down to the woods, unless they are privately owned, have no public access and you have the landowners express permission.
Hope that helps