Hello @Gareth29,
Making a reservation means you're entering into a legal contract so you must be old enough, at the time of making the reservation, to enter into a legally binding contract. That's 18 in a lot of jurisdictions.
Airbnb's terms of service require that you must be 18 to register an Airbnb account.
Presuming that your father will not be going on the trip with you, one issue with using his account is that that would then be a third party reservation. The rule is that the holder of the account from which the reservation is made must check in and stay at the listing. Airbnb doesn't officially support third party reservations and many hosts will not accept them.
You could try using his account and explaining the situation to the host. You may find someone willing to accept you but do be prepared for declines or cancellations.
Steve.