I'd just leave it alone until you actually need to do something to it. Get used to the gun and how it performs. You'll know what it needs after a couple of games.
The dust cover on G&G is held closed by a spring and is opposite what most other armalite AEGs. With others, you just cock the charging handle and the dust cover springs open. G&G mount the spring backwards to keep the cover closed and have no other locking mechanism. Just pry it open with your fingernails or a small flat head screwdriver to get to the hopup adjustment.