Welcome to Maryland. So sorry you got dragged into our mess.
From my understanding, the law prohibits things like recording phone calls that originate in Maryland without their knowledge. Similarly, you cannot tape conversations in secret unless in private places. The basic rule is to ask. Our cops use body cameras and will ask and will turn them off if recording is refused. Usually, if such is the case, get a recording of the request to turn off the camera recorded, and then turn it off immediately. Baltimore City does have a city wide surveillance system, but there are more practical reasons as to why you don't want to go into Baltimore City with a camera and let people know about it... or just going into Baltimore in general... we're currently the national leaders in homicide (Baltimore County is not Baltimore City, so that's fine.).
I am not a lawyer, so it might be better to call a legal office and ask for advise as a consultation I'm not sure of any specific practices. Also keep in mind that restaurants probably count as private property for the purposes of this law, so it's better to keep the recording areas limited to public streets, sidewalks, parks, and government buildings that are open to the public (town hall meetings and the like... for safety concerns, do not try it at schools during the course of normal business... recording your kids basketball game or pageant solo is fine... but not during the normal school day).
Do you feel comfortable discussing what you intend to use the footage for? Documentary? Humorous pranks? CYA with the Police? Just to further clarify.