How did you pay? If credit card then call and they can credit you and cancel his payment. If paypal then file a dispute and they will freeze his account until it is settled. If by check then stop payment.
More than likely it’s just the clutch plates stuck together from not being used. Just get it running, put it in neutral, sit in it and pull the clutch in and put it in gear with the tires on the ground there is enough load to break the friction discs free from the steels.
The other way is pull the clutch cover and hold the clutch lever and pry the plates apart with a screwdriver.
As far as the travel I don’t know how much exactly but enough to disengage it but not too much or the plates will slip out of the basket.