FOUND - my sister knew it. The Noob Warriors but Scott Douglas.
I think I read it 4-6 years ago (I'm not even sure if its an officially published book or an online one)
Basically what I remember is that this kid (I want to say girl but might have been a boy), gets taken away to fight this long standing war and its got 1984 vibes, big government influence and it kind of seems that the war is put on by the government to control people. Also at some point, kid is with a bunch of soldiers and the commanding officer is calling their side one type of cereal and the enemy another (I feel confident one side was the Corn flakes or Frosted Flakes, not sure about the other one)? I don't remember if there is some love triangle going on, I do think there might be an older sibling who went away to the war and is now missing kind of thing. Only other thing I can remember is that the kid lived in a neighborhood, I think in like a "so perfect its weird cause it was put together by the government" kind of way? And the parents were a little checked out maybe. Any help would be appreciated.