The Google Assistant has to be my favorite new feature in the Pixel phones. You can ask it so many things and it can provide some really useful information.
Even better is the customization you can do very simply by entering the settings in the assistant. By simply long pressing the home button to launch the assistant, you can then tap the three dots on the top right to show the menu. From there just select the settings option.
In the settings, you can select what news sources are used (which has a lot of options), customize what information is provided when you ask about your day, or see the shopping list that is used for adding items.
In addition, you can easily modify personal info such as your home and work locations, what the assistant uses for your own nickname, and set what weather units you use (Fahrenheit or Celsius).
This is a great feature to let you get to what information you want specific to your own needs and likings.
Hope you find the customization settings as useful as I do.