There are no hills between the Tuscan Inn and the San Francisco Port. And the Tuscan Inn is close to the Port. The problem is that you have to cross a fairly big street (Embarcadero)with luggage to reach the Port
I suggest that you contact the Tuscan Inn and see if their van is available to take you and the others to the Port. It is five to 10 minutes or less from the Tuscan Inn to the port by car. If they do not have a van, taxis are readily available in San Francisco, but get a firm price first (and it should not be very much because it is a very short ride).
It isn't so much the distance but rather the traffic that makes going by van or taxi your best option.
Hope that this helps,