Re: Aggression towards food & toys as a puppy
4 months old is very young, and it would be hard for me to separate play growling with the toy, from resource guarding with the toy..... all my dogs have horrific growling behaviors when playing, sounds just like they are going to kill each other (or me if I'm at the other end of the tug toy).
The food thing between the 2 wouldn't bother me either right now. Just a warning to keep the other one away isn't uncommon. My 'pig' Bretta eats WAY faster than Elsa. So she wanders close to sniff the ground for scraps when Elsa is finishing up and Elsa will normally growl to make sure Bretta doesn't actually get her nose in the bowl.
And my dogs do have the right to eat without having to worry about another dog coming into their bowl. You may just want to feed your pup in it's crate so they can eat with no worry at this point.
Good luck with both these puppies. Most of us wouldn't have taken 2 such young dogs on so you will have your hands full. The quicker you can get into dog classes so YOU will gain the skills to be seen by your dog as in the Leadership Role, the better.
Just as heads up for how much harder it is for you with 2 dogs so close in age, these are good sites for preparation: