Buy at least £2k worth of gear, then come back and ask about upgrades before you've even taken delivery of your guns.
I jest of course. As above, check where your nearest site is and keep and eye on their Facebook page for events when this is all over. If you're determined to be as prepared as possible, a sturdy pair of boots with good ankle support and perhaps some decent full seal eye protection and lower face mesh will be all you'd need for your first few games.
Don't buy a gun yet, by all means have a look at what you like aesthetically speaking but you'll never really know what suits you, until you start playing and can get a long to a shop to actually hold some.