If you are staying overnight at the Historic Inns of Annapolis, they have valet parking right out front of the main building (Governors Calvert House) where you check in. If you are not staying overnight, you can use the Calvert Street Garage which is free on weekends and about a 5 minute walk to Historic Inns of Annapolis.
Check in is at 4pm, they will try to get people in early but can't guarantee it so you should plan to get ready/dressed prior to arrival.