AF #1 (for spoken language, at least) is incorrect, that would be "air force number one", but the correct title of the plane which the president is riding in is "air force 1" (AF1). It is the callsign of the plane. If it is a helicopter, it is Marine One. One, here, means "unit number one", the most important military unit.
yes - 'ride in' is the same, it means that during the journey, you will be seated in that particular vehicle
by the way, we'd probably say 'ride on AF1'. but ride in is also acceptable