Fishing w/Kids

Hi All, New to river fishing and semi-new to this area (Merrimack Valley), but old hat at fishing in lakes/ponds. Maybe the water temp is too cold yet, but I've been skunked three times now, abet all from the shoreline. I bring the kids who are fairly new to fishing, so I don't want to lose their interest for lack of catching fish as so far they truly seem to enjoy fishing. So far, I've tried under the 495 bridge by Ward Hill/B.J.s side(crazy to get too, made our own path), under 495 bridge on Lawrence/Andover line, and thinking about trying from the Yacht club in Bradford. I've used live bait, worms, spinners, even tried corn for maybe a carp (lol), all to no avail. I've never fished in this area, let alone in a river, but it's close and have read stories and seen the pics of the fish being pulled out of The Merrimack. Any insight would be appreciated, and thanks in advance. Fishing w/Kids