Fowlsheugh is between Stonehaven and Catterline and you could be lucky to see some puffins if you follow the walk along the cliffs
Inverbervie has the original figure head from the Cutty Sark, just on the right as you go over the bridge. Decent chip shop too....or it used to be, pebbly beach i think
Gourdon or Johnshaven, nice for a leg stretch and a look at the old habours if you like that sort of thing. Gourdon has a newish fish restaurant but don't know if it's back open or not yet.
Beach at StCyrus is lovely, and there is Steptoes Yard if you are looking for any old furniture or general shite knickknacks
Charleton Farm...just before Montrose, fruit picking decent cafe, and large play area for the children .
Montrose also has a beach and the Seafront Splash, Roo's Leap is usually good for food
Lunan Beach is wonderful but is difficult to find and there's been a bit of a stooshie over parking there recently!
Auchmithie is pretty, nice beach b ut steep walk
Arbroath....nice harbour, easy parking usually, chip shop and iceycream shop right by the harbour.
Or if you like smokies go to the Bell |Rock Chipper!
After Arbroath you have to make a conscious effort to get off the dual carriageway to Carnoustie or Broughty Ferry ...i don't know either of those well.
Also you have Monikie which is nice for a walk...lake/reservoir
Into Dundee you have the V&A, and The Discovery, or further round Camperdown Park /Zoo