I don't fish up there so I have little to recommend (and as a practice I don't mention spots online) but I can give you a few details on what to look for on your own... Find places within a reasonable walk from where you can legally park a car and access the shoreline, find rocky areas along shore (wearing Korkers !!!), go down without a rod a low tide and look for holes and rocks and bars and any kind of structure AND LOOK FOR PLACES TO GET OUT OF THE WATER WHEN HOLDING A FISH- go back at high tidde, see what you have to work with, see how the water moves over these spots with the tide running. See where the rips are, the whitewater, any streams dumping in, BAIT see if you can find bait. Once you've scouted around a bit, go back - with a friend that fishes - and fish...
That's a start
..
Also, get the OTW book for shore fishing the Cape...