You can manually turn the "do not disturb" on and off every morning, or you can set it to automatically do it every day.
I have mine set so after 11pm, "do not disturb" kicks in and then at 7.30am it switches off and i have slightly different settings for the weekend.
The following is for my Xperia XZ2 Compact, so I'm hoping yours will be something similar:
Click on "settings", then select "do not disturb". Scroll to the bottom and select "turn on automatically" (Mine has "3 enabled" underneath, as I have 3 rules set). From here it should be fairly straightforward to set your own rules.