There is no better way to learn science than building your own things and conducting experiments. The idea of levitating water droplets and even ants with acoustic waves is nothing new. Asier Marzo has shared a guide that gives you an idea how to build an acoustic levitator.
You are going to need 72x 10mm 40kHz transducers, an Arduino Nano, 9V DC adapter, and 3D printed components to pull this off. You can buy the kit for $70 at this time.