[Pocky]

I'm assuming the field you're talking about is Ultimate Airsoft, if so hope to see you there sometimes (I'll be the guy with the tan vest and lightsaber). Anyways I'm a new airsofter (6 months) and this is what I did:

-Eyepro
-Bought a G&G cm16 raider at badlands paintball on a sale ($160) and batteries
-Bought 2 midcaps, a valken m90sp spring, sling, smart charger, and a reflex sight all on amazon/aliexpress
-looked at youtube and gearbox animation and did the spring change following a tutorial

I recommend you buy a new gun, more pew pew and less tinkering, over time you'll learn how the guns work and you'll me more confident to tinker with a used one.
If you are not mechanically inclined, a gun with quick spring change or split gear box (i.e. ICS) would be good.
You don't need to buy everything now you can build it over time when you find out what gear you really want. I guarantee half of the stuff from that deal will end up under your bed collecting dust a few months in.