SOT on any of the local lochs.
Loch Morlich is most popular. Easy access, beach cafe, a nice wee creek to explore.
Loch an Eilean has a wee carry but is smaller/more scenic. There’s a castle on an island that you can easily paddle round.
Loch Pityoulish has more difficult parking and a gate to manoeuvre with the SOT but is rarely paddled.
Further afield, Lochindorb has a bigger island and a ruined castle to explore.
There’s an easy river paddle from Ruthven Bridge at Kingussie through the Insh Marshes and into Loch Insh. Don’t take the SOT out at the boat house – they’ll have a strop. Go just beyond it to the outflow, past the island and to the bank beside the church. Good parking here too.
Remember that the Scottish access laws also apply to water/waterways so you can basically paddle anywhere you want.
Kids will easily handle a circuit of Loch Morlich, Speyside Way to Boat of Garten and some of the trails in the woods beside Carrbridge.
Loops from town? Where to start. Up the Old Logging Way to Badaguish and round that course, up the bottom bit of the Lairig Ghru and back down again. Burma Road. High Burnside if you want to get your steez on. So many more…..