I'm making a shoe and I would like to knoe how long does gumpaste takes to dry, I made the sole first and I'll make the rest tomorrow, will it be dry by saturday??

Should be. If you think isn't not put it in your oven with the light on and nothing else. In other words don't turn the oven on just the light in it. Also make sure to turn it over to help promote drying both sides.

Does it takes longer than fondant?

Gumpaste dries quicker than fondant, part of the reason it's used for flowers more than fondant.