Forget about the Northeast River with your 4.5' draft. There's not much in the way of anchorages or marinas available.
Havre De Grace has Tidewater Marina otherwise no place to anchor out and be comfortable. It's a nice little town with a couple of resturants and an very good ice cream shop.
The Sassafras River has a number of places you can drop the hook as well as several marinas in Georgetown. Forget Betterton. While they have a town dock is so loaded with bird crap that I wouldn't set foot on it. A nice place to anchor is just past Ordinary Pt on the South side of the river, just outside of Turner Creek. You'll also find a number of boats to your right just inside the No Wake Zone prior to reaching Georgetown. Beware the depth goes from 20' to 5' suddenly. It's a sandy bottom with decent holding.
Still Pond is a nice place to spend an evening or two. There's Still Pond Creek to the far left after entering. Do not try to go in. It takes local knowledge and is very shallow in parts. Instead stay in Still Pond itself and tuck as far in past the western point of land. Getting in past the point helps block the wakes from the barges running outside in the channel. There's apx 8' of water throughout the anchorage.
Worton Creek is one of our favorite spots. It's open to the west which will provide you with some beautiful sunsets. The closer you anchor to the mouth of the creek, near the red marker, the less you'll deal with wakes from boat traffic. Note that traffic settles down at night and you should sleep peacefully.
I would pass on Fairlee Creek. It can be difficult to get into as the channel twists a bit. Additionally it's a hot spot for the muscle power boat boys and girls and can get crowded and noisey.
Rock Hall if you choose to go further south is a nice town with a number of marinas. Too many options. Ask for more info if you think you'll stop there.
Good luck and have fun.