Being that we're in the Adirondacks, there are plenty of beautiful hikes in the area, for kids of all ages! One of the easiest ways to find a good hike is using the AllTrails app/website. You can filter by length, difficulty, views, etc and see other people's photos and reviews. We do have some tailored recommendations, but this website is another great resource!
Downtown Lake Placid has it all! If you'd like to do some shopping or grab a meal out, you'll have plenty of options here. Just park in one of the parking lots available (the largest one is on Main Street across from where Main Street and Parkside Dr intersect) and peruse to your heart's desire! *Note that you will have to pay for parking, but you can do so by credit card.