How long does it take to get rid of that smoke smell?Heeeellppp!!?

Im 12(iknow,ToYoung!!) And Me And My Bff Tried Smoking In My Shed, Its Sports Day, So ourmums let us off, shes at work, and my brother will be home in an hour!! how long/What shall i do, To Get Of The Smoke Smell!!AHHH!! Heeeeeeeeeeelllllpppppppp, Nothing mean:)