Is that the level 1 or level 2? If you got the lvl1 you'll need to upgrade internals at some point since it's stock WE.
JT Paintball face mask is a good beginner mask, and protects your mouth and doesn't fog.
If you want googles/face mesh, you'll need a decent pair of googles that are pretty pricey.
Shoes - If you play indoor you can wear whatever you want, good ankle support isn't a bad idea. Outdoors you'll need some decent boots that aren't to heavy and water proof.
BB's - make sure you run quality bb in GBB, preferably not bios.
Clothing - If you play CQB just buy some cheap walmart pants and t-shirt/sweater, under $20 for everything. If you are more budgeted, get ventilated clothing (underwear, shirts, etc) -> Under armor.
Gloves - Mechanix gloves are a big hit, you can buy them at Canadian tire, get the thin pair, around $20-30.
BDU - Don't need unless you play out doors really.
Plate carrier, or chest rig - look up condor stuff, relatively cheap and can be found locally. Great quality (MCR6) comes to my mind - easy beginner vest, holds 6 mags and can add additional pouches to it if needed. Around $45-50.
Knee pads - a must.