Hey there, as a beginner myself I would say start with a gun, once you have that sorted the vest and pouches would depend on the gun, no point buying pouches for a M4 if you have AK mags etc...
Also it depends where you play for your kit. And as I play indoors in the dark mostly I went to Primark and got black combat trousers and a long sleeve tee shirt. For a beginner go for cheap stuff, I hit Ebay hard when I first started, got a mask, gun sling, belt, mag pouches, knee pads and pistols holster from there, nothing cost much more than a tenner for each item.
This is pretty much the extent of my current loadout.
However I am looking to do lots of outdoor skirmishing next year so will want some sort of multicam set up with a decent vest and backpack to carry all my gear.
But like I say, the kit doesnt need to be to spec or expensive and also be careful not to buy things you dont want or need, I built my kit up over 4 or 5 skirmishes, realising after each one I needed something else. On my first visit to an Airsoft shop they tried selling me over half their stock "now Sir, you need a vest, this one here is only £89.99, also these gloves at £25.99 go great and match this mask at £85.99 GRRRRR
Only thing I would reccomend spending money on is face protection, either a cool AND COMFORTABLE full face mask, but make sure your visability is ok, or a decent pair of goggles and lower mask.