Practice juggling. Buy 3 juggling balls (you know those bean bag types that don’t roll away), and keep them with you. Don’t use tennis balls, because they have a tendency to bounce and roll. When you have some downtime, start practicing. Watch a few video tutorials to get the hang of it.

If you can have a backpack with you, consider bringing a tablet with you. If you have one with a pen, you can draw. Watch a few more tutorials, and learn to draw something you like. Landscapes, portraits, fantasy dragons, pokemons whatever.

Tablets are also fine for reading ebooks. Check what your local library has to offer. Maybe you can borrow library books and read them on your tablet.