There are many built-in nodes you can use to make your compositions interactive, including:
vuo.mouse for getting input from a mouse or trackpad
vuo.keyboard for getting input from keys typed or pressed
vuo.hid for getting input from a USB Human Interface Device (HID)
vuo.leap for controlling a composition with hand and finger movements from a Leap Motion device
vuo.osc for remotely controlling a composition via a TouchOSC interface on a phone or tablet