Need some help finding training resources

Hi, I moved in with my fiancé and his family and they have 7 dogs. 4 of which are older mutts (2 males, 2 females), 1 puddle mix (he's younger than the 4 but about a year older than the 'trouble' makers) and 2 young female mutts (about a year and a half, maybe 2). . None of them are trained. They know their names (as far as I've noticed) but they fight a lot. Growl over food, and even have started to fight, as in one of the younger ones would growl at one of the older ones and the other young one went for her neck and vice versa. (They are kept separate for a period of time after such a thing happens, now even given food separately but not behind a door so if other dogs finish before they get close). . I've looked online but I'm not sure what resources are credible. I'd preferably want to have the youngest three semi trained or at least learn how to deal and prevent these situations in the future.

Thanks