Engine light, airbag light and the code p302 all come up for my 2007 chevrolet aveo

The check engine light will come on anytime the power train computer senses a problem that sets a code. The code you have P0302 means a misfire was detected on cylinder #2. At the front of the engine (where the belt is) is cylinder #1. Cylinder #4 is closest to the tranny. A misfire could be a bad spark plug, wire, ignition coil or fuel injector. The most common problem is usually the spark plug. Remove it and check for a crack in the porcelain, or the electrode on the end being damaged. As for the air bag light there is really no relation to the code. This will also need to be diagnosed, as they set codes for the restraint system totally independently of the power train computer.