There are plenty of settings that you can toggle for Google Assistant covering everything from privacy limits to languages to which voice you want to hear from. It's always been a scramble, though, to tap into those settings as they're several taps into your Google Account settings. Now, with the latest update to the Google app, Pixel users will be able to access those settings from their system settings.
Some users are now seeing a new "Assistant" item in the Apps & notifications section. Tapping on it will bring you a couple of toggles for accessing Google Assistant, either by a "Hey Google" call-out or squeezing the sides of the phone. It also has a handy one-touch link to all Assistant toggles in the Google Account settings. This should roll out to all Pixel users over time.
Check the Play Store for an update or download the beta for v10.53.3 of the Google app from APK Mirror.