Whoa... I love a lot of things about this already, like the part when you described Billie as a child at heart playing video games. XD
For some reason my last comment never posted, sooo I'll go back over what I said before, for starters, I loved the summary and the first chapter, there are so many Green Day fanfics out there, but this one is definitely different and I'm intrigued to see where you take it. I love that it's different from other stories and it stands out
Plus Karen seems like a pretty damn cool character already, she strikes me as a punk at heart.
Sooo I'll get out of your hair, keep writing! And PS, I loved how ended I Was Only Dreaming keep it up!