Wearing a pair of gloves is a good idea as it hurts when you get shot on the hand, cheap ones will suffice in the short term so long as you can still safely handle your airsoft replica.
A hat or head wrap is advisable as headshots can hurt. Headgear will also improve your camouflage, but it is not mandatory. Be conscious of how a hat may interface with your goggles.
When you start playing more seriously you may want to buy a waterproof ‘Gore-Tex’ jacket and a warm clothing layer, in case you get caught out in the rain or have to wait for game start in the cold. You will shrug off most of the effects of cold and damp when you exert energy in game, but if you really get caught out and become uncomfortable then you will find that your performance drops dramatically. Worst of all, you might cease to enjoy the game.