In this case
-qq is an option to apt-get and not bash. If you do man apt-get you will get the documentation for apt-get.
It means "really quiet"
Quiet. Produces output suitable for logging, omitting progress indicators. More q's will produce more quiet up to a maximum of two. You can also use -q=# to set the quiet level, overriding the configuration file. Note that quiet level 2 implies -y, you should never use -qq without a no-action modifier such as -d, --print-uris or -s as APT may decided to do something you did not expect.
So, to summarize a call to
apt-get will be more verbose than
apt-get -q which is more verbose than
Generally the first place to look for any help on a command is that command's "man" page.
man is a standard Linux command that will display help for the given command. So in your case,
man apt-get would give you help for the apt-get command.