Downtown Laramie offers great shops, eating, and a playground.
Hiking is great just right outside of Laramie. The turtle rock trail is perfect for an easy quick hike.
Curt Gowdy is about a 30 minute drive from Laramie. It has a ton of outdoor activities including hiking, fishing, and water activities like paddle boarding.
If you're looking for an afternoon activity this is a great option especially for kids.