should you shut down or sleep mode?

It makes no difference. The Macs in this house get restarted with System Updates. Other than that they run 24/7/365.

I use sleep mode when I am actively using my Mac but will be away from it for 30 minutes or so, usually for a break or a meal.

Other than that, I shut down my Mac when I'm not using it.

I shut down daily. I like to restart every morning as it also clears out some files and erases my old junk mail.

I shut down if I will be away from my computer for an hour or more. Others never shut down. I guess the choice is yours.