BE POLITE TAKE A GIFT
If you are visiting a friend because you were invited for dinner or to spend a few days with them, make sure, you take a gift (a bottle of wine/chocolates or flowers).
Please, whatever you do, do not fuss about food, eat whatever is offered to you. If you have food allergies and you have been asked “ DO YOU EAT EVERYTHING ?”, be sincere and tell about your food requirements. Is very embracing for your host to find out, 2 minutes before dinner, that you are allergic to whatever they are serving and that will reflect into the other guests that the host is not a considerate person.