Make homemade instruments.
Blow over the top of a glass bottle. Put wax paper over a plastic hairbrush for a kazoo. Put dry beans in a plastic container for a shaker. Stretch rubber bands or string over a box as a guitar. Make a cube out of wood panels, each with a different thickness for varying tone; cut a three-inch hole in the bottom or side so the sound can escape.
Master that before you pay hundreds for decent instruments.