*Disclaimer* I haven't done the northernmost 75 miles of PA yet, which many people say is the worst part of the rocks.

However, I'd argue that starting in Harper's Ferry and going north is a good place to start out (assuming the bridge over the Potomac is repaired by then). MD is mostly pretty easy: it's mostly flat, and the few climbs are pretty short. There are a few rocky sections in the northern part that will give you a small taste of what the PA rocks are like.

Southern PA (up to Duncannon) is as easy as it gets on the AT. I'd be considered a slow hiker by most, and I averaged 15 MPD on that section, no sweat. The rocks are few and far between until you get to the last ridge south of Duncannon. In fact, the rocks didn't really get annoying for me until north of Swatara Gap. Then you start to get into the parts where the trail is just a bunch of jumbled rocks sticking up at random angles. But, by then you will have been on the trail for 2 weeks and should be in good hiking shape. Just take it slow and you'll be fine.

I do agree with the people who say this section isn't that great in terms of scenery, and it definitely doesn't feel very remote at all. There are some occasional views along the ridges, and the section of open farm country between Boiling Springs and Duncannon was pretty neat, but that's about it. Also you'll get differing opinions from different people on this site, but IMO the Doyle in Duncannon was a pretty cool town stop.