A mask is the most important part of your airsoft loadout because it protects your eyes.
You cant play airsoft without your eyes right?
I recomend using a paintball mask at first so you dont have to suffer the painful face shots. They will fog if you don't have defogger.
I also recomend using mesh masks because they dont fog, and provide good protection.
Personally I use mesh goggles and a iron face because i can take off the mask part if it is too hot out.