I wonder if it's posible to create more than 3 giveaway ?

welcome to steamgifts. yes it is possible. The more you give away the more slots you get. But for the beginning you only have 3 until you gave the keys to the winners.

FAQ

Hi, thanks a lot, i will wait for my giveaway to end then :D

You can write ticket to support, they will give you some temporary slots.

yes