My car consumes a lot of gas and has a check engine light on

Well p0302 is a misfire on cylinder 2 so I would start by changing the spark plugs, whatever plugs the owners manual calls for will be the best you could ever put in for power and fuel economy

I did change out all the spark plugs with new ACDelco plugs and replaced that ignition coil with a brand new coil still having the issue should I change out the rest of the ignition coils

The old coils looked great too checked no condensation no oil on any of the plugs completely dry and the Chamber

Do a compression test. If compression is lower on that cylinder than the rest youll want to want to put that cylinder at TDC and gently force some air into it and find out where the air is going. Google "leak down test", You can use a small air compressor with an air wand and a piece of hose to force the air in, most people don't have a leak down tester (myself included) but this is a cheap and easy way to do so. I suspect you may have a bad valve