Open your trunk and near the back of the trunk( close to the back seats) there should be a "flap" that needs to be in place for the top to work. Pull that flap towards you and near the front there should be two slots that the flap goes into. It is a safety device so you don't wreck your top or crush something that may be in the trunk.
You should slap whoever sold you the car for not explaining anything about your car LOL.