Vinegared Ginger (gari) is used between dishes as a palate cleaner. It is not meant to be eaten in the same bit as sushi.
When eating noodles, it is fine to make slurping noises.
Saki can be either chilled or hot, depending on how you like it.
Talk to the other diners around you. Sushi is about community, so start a conversation.
Don’t be afraid to ask for things such as Kazunoko, inago, hebo and idtakko that are not on the menu. Usually they are available, just not advertised.
People who handle food never handle money. Have another employee assist you with settling your bill. If you wish to tip the chef, use the tip jar provided.