If you do any of these, I would LOVE to see what you do and make!
Stop Motion Video!
For the uninitiated, stop motion animation is a film making technique that makes inanimate objects appear to move on their own. Think Gumby or Wallace and Gromit.
To make it work, you place an object in front of a camera and snap a photo. You then move the object a tiny bit and snap another photo. Repeat this process twenty to ten thousand times, play back the sequence in rapid progression, and the object appears to move fluidly across the screen.
Make some noise!
Below is an instructable for a series of instruments you can make at home! Ideas range from a homeade "flute" to a "saxaphone"
https://www.instructables.com/id/The-Most-Annoying-Sound-in-the-World/ (for the most loudest and most annoying if you want to drive your sibling crazy)
If you wanted to get a little... medieval, make a really cool catapult! I admit, I've made a lot of catapults in my day, but this one is powerful, durable and easy to make!
Got some Spaghetti, tape and a marshmallow and see how high you can build! This activity has been used throughout schools and universities around the world to teach problem solving, prototyping, design, team building and so much more!