Best power saving settings for screensaver?

I'm a bit confused regarding the different types of power saving (screen turn off, sleep) available on Windows 10, and would be grateful if someone could suggest the best set-up for my situtation.
I turn on my home PC every morning when I get up, and turn it off before I go to bed. I work at a university, but am not there every day, nor all the day, so I prefer to leave my PC in standby when I'm not using it.
I have a particular screensaver which I like to have running when the computer is idle.
I don't want my PC going into standby while I'm downloading or uploading big files that take quite a while.
Thanks.
Florio