Bad Obsession has given lots of detail. I will only add that Chesapeake Bay sailing is a great step up from lake sailing. I highly recommend it.
Just check the weather forecast before setting out. In the summer, we can get some pop up thunderstorms, so you will want to avoid being out in those times. Also, the further north you are, the more sheltered and closer land is, usually.
Mid-Bay is great with great towns to visit (Annapolis, St. Michaels, Oxford, etc.) and also has lots of places to anchor in quiet coves. Just get a good chart chip for your chart plotter, or a handheld GPS or a good app for a smart phone. Before you go, read up on the area and get a cruising guide such as Cruising the Chesapeake, A Gunkholers Guide. There is a lot to do and see in the area, and boating is a great way to do it.