As many suitcases as you like, but ideally each one should not be over 23kg. You need to put a luggage tag on each case -we put two on each, to be safe!
No tags needed on hand luggage.
Drinks can go anywhere. Normally it is safer to put them in your hand luggage.
If you are talking about parking for this Easter you have left it very, very late, so you will struggle. Try Parking4cruises.
If you have no joy, use the public multi storey at West Quay (£5 a day,) and take a taxi to the port.