I poo-poo the warnings :smash: . I've lived in Italy, Germany, Japan, and a few other lovely places. Don't bother stocking up on things you can live without. If your child has specific needs (Jumbo crayons were impossible to get in Japan.) get those or if you have a favorite bra, hair color or whatever, take a few.
The water in Italy was awful. We had to use bottled or free filled bottles from post for cooking, drinking or even teeth brushing...It was a pita, but it was a long time ago and may be better today.
Friends, I was a military brat and my best friend in Germany was there with her Civ. dad. You may feel left out a bit by the number of military functions, but most civ families are invited. When I was an Army wife, many of my friends overseas were expats from the US and other countries.I also made a number of local friends from every country; they were the best guides to everything local.
The outdoor markets in Italy were awesome. I got the best undies there for next to nothing. It was strange to buy them from a vendor who wanted to haggle, but a lot of fun and a great deal.
Don't freak out, it will be an adjustment, but probably the best adventure you guys will ever have. .