Now some folks ( Including me) might say it is rather presumptuous to send a contract over to a gallery that just gave you a foot in the door (especially if you are just having one or 2 pieces in a group show - which is usually how a gallery will “try you out” to see how your art goes over with their collector base and also what you are like to deal with.. )
But at the very least you should have an email exchange with the curator that spells out what the terms of your exhibition, affiliation or representation are.