Will it work? Yes.
Will it work well? No.
Will people laugh? A lot.
There is a certain minimum expectation in terms of investment and appearance associated with playing airsoft. It seems like you're going to have to buy either a pod belt or a tac vest, so why not invest in the gear appropriate to the activity you'll be participating in?
Not to mention that you're underaged. If your local community permits you to participate, the least you can do is to not show up wearing paintball gear.
"The Bird of Hermes is My Name, Eating My Wings to Make Me Tame."