Where can I get lighter fluid for my zippo ?

I bought a zippo at a market, but it ran out of fluid. I'm underage to buy the lighter fluid so where could I get some or is there something I could use ? Preferably something safe.|||na you can get it i got mine and im 13 so dont worry but mi profile says in 17 but yea any way you can ge in i got mine from the market and in blacktown.