Amsterdam is actually great with kids. The Rijksmuseum is too much at that age, but the Van Gogh Museum is not, especially with the Pokémon speurtocht they have now. Nemo is also excellent, as is Ripley’s Believe it or Not. When you take the tram, try to sit by a monster window – you close one eye and bob your head up and down to ‘eat’ the pedestrians you pass.
The area around the station and Damrak can be a bit grimly touristy, but away from there and it’s fine. Vondelpark is lovely to wander around on a summer’s day, and PC Hoofdstraat next door is great for people watching and people watching watching – it’s full of vulgar expensive shops and supercars.
You’ll find lots of good eating pretty much everywhere, but you should also try shitty snack food from a wall. A broodje kroket is deliciously awful.