2001 Pontiac Grand am Errorode P0300 random or multiple cylinder misfire

Hello I’m having issue of a code p0300 random or multiple cylinder misfire detected .

First off I have fixed all other issues posted in past .

The car has been sitting for a month with gas that is maybe a little older .
It is parked due to none payment of registration so I had to put a non-op on it .
When I parked it it had very little gas in it . Ice has formed on the car sinced parked .

Could this be bad gas ? Or is there another famous Pontiac problem ?

Any help would be greatly appreciated thank you.