In Chesapeake City you have 2 or 3 choices, depending on timing, luck and needs. The first is the city dock. it is rather short and has no services, IE not water or electric, or facilties, but you get what you pay for, it's free. The other down side, it is first come first served so your chances are slim.
The second is anchoring in "engineers cove" The holding is great and you are protected.
The third choice is Chesapeake Inn Marina. They almost always have dockage. their web site is
http://www.chesapeakeinn.com/, and phone number is 410.885.2040. Andy is the dock master and sometimes he can be hard to get in touch with, but he will get you a slip. One consideration about if you want a slip, is that on the weekends, it is a party bar, it can get a little lound even on the docks.
Chesapeake City is a cute town, that can keep you ammused for a day or two.
When in july are you going to be there? I will be there July 19th, with 10+ boats.