MacDuff Aquarium is good. About 40 mins from Huntly. Check the website for any special events. The Dolphin fish & chip shop just along the road is lovely & you can use the aquarium picnic tables to eat at.
Dean's shortbread factory in Huntly for lunch. Nice cafe/restaurant with a viewing gallery so you can see the shortbread being made.
Take a picnic to Huntly's Deveron park by the river. Playpark & Nordic ski centre close by.
Asda is usually better stocked than Tesco.
Portsoy, about 40 mins drive. Pretty, lovely ice cream shop on the main street & nice little beach.
Collieston. Pretty little village, nice little bay & beach. Aporox 45 mins.
Speyside whale & dolphin centre about 50 mins drive. Well worth a visit. You often see seals as well.
If you want to make a day of it there is a lighthouse & museum near Fraserburgh. It's about 90 mins drive from Huntly. Often done as a school trip as quite educational.
Falconry Centre about 20 mins from Huntly. Highly recommend this. Lovely birds. Flying displays & you get the chance to join in. Staff really passionate & knowledgeable. Small cafe as well.