Cherry Hill to Lancaster is not a bad ride but you want to avoid traveling during rush hour.
I-95N to MD-32W to MD-29N to I-70E to 695N to I-83N to PA-30E
These are all major roads with no lights until you get to 30E in PA.
Lancaster has quite a few campgrounds. All of them are decent. Everyone has their own favorite.
I like Country Acres. It is well run,clean in a very central location but slightly off the beaten and away from the heart of the congestion.
Second favorite is Old Mill Stream not quite as pristine as Country Acres but still a nice park. It is well run. It is in a very central but somewhat busy location right on route 30.
If you have kids there is a small kid amusement park right next door.
If you like breakfast be sure to check out Shady Maple Smorgasbord
You could take the Market St. exit instead of the 30 East exit and avoid a few red lights through the shopping area, but 30 is a direct exit.