Apple - How can I run unzip silently in terminal?

As stated in the manual, -q (quiet) or -qq (even quieter).

unzip -qq filename

If you don’t want to see the output from your terminal commands then you can redirect both standard output and standard error to /dev/null by adding > /dev/null 2>&1 to the end of your command. Of course, this can hide errors, so you might want to redirect it to a file instead, depending on your use case.