Hello Wantoldfocus!
You can set up Focus one time, and it will turn on and off automatically at the times and dates you had pre-set. So you never have to turn it on, or off again!
To learn how to Use Focus on your iPhone or iPad - Apple Support, please see this Support Article.
To silence your iPhone whenever you need to, you can just turn on Silent Mode by pushing the switch on the left side of your iPhone away from the screen, so that it shows red. Then, when you want to receive audible notifications again, just pull the switch towards you, and the red will disappear.
I hope this is helpful. Good Luck!