You've already gotten some great advise! Since you're shore bound, you should spend some time browsing the MD DNR website. There's information there that shows state & county Parks & boat ramps which have shore fishing available. (They used to publish a paper map of parks & ramps, but I'm not sure if they still do.) Google Maps will help locate them & the satellite feature will help show you a truer image of the actual conditions you might encounter. At least I've found it to be some help at times.
Near Solomon's, right where the Rt 2 & 4 bridge crosses the Patuxent River, there is a fishing pier, but I don't know if there's anywhere to fly fish. I've been down there many times but have never fished at that location. There is also (or was, 9/11 changed a lot of things) some shore fishing access on the bay side, up near Calvert Cliff's. Surf fishing used to be allowed, but again, I don't know how well you might do with a fly rod. I've fished there many years ago, but was using surf equipment & bait. If it's within possibility, getting some type of watercraft would give you a lot more options. Kayak's or canoes would be a good choice, and even a belly boat can be used in many locations. Wading is very limited all over the state in tidal water, primarily due to access limitations & mud or silt bottoms not suited for wading.
At one time or another I've fished all over the state, but never did a lot of fly fishing in Southern MD. Most of the fishing I get to do now is primarily in locations on the Eastern Shore side. I live up near Annapolis!
Feel free to contact me if you have questions, I may not be able to answer all of them, but perhaps I can get you headed in the right direction.
And, for flies, add some Seaducers too!
One more thing, US Rt 13 does not cross the bay bridge! Rt 13 runs north & south on the eastern shore side of MD from the MD/VA line on the south end, and the MD/DE line on the north! US RT 50/301 crosses the bridge near Annapolis! If you wish to use Rt 13, it crosses RT 50 @ Salisbury, MD. ( I drive a tractor trailer for a living!)
Ard, I knew what you meant, but that could get very confusing to a newb to this area!