You will need something called a "regulator". It regulates the high CO2 pressure down to something more manageable. They are not sold at your big box hardware store. Check welding supplies, fire extinguisher places, brewers supplies. Or online. Type "regulator" into the search box above, and read about them.
You also need a solenoid for the on/off, and a needle valve to fine tune the bubbling. Some regulators already have these things connected.