The built in tools are badly suited for this. Look up the wiki manual for a transparent proxy, so that you proxy all web traffic (you can only proxy HTTP transparently, for HTTPS to work you have to reconfigure all user browsers to explicitly use the proxy). Then turn on logging of the proxy topic (the the "system logging" wiki manual). Then log all proxy logs to a remote syslog server and use whatever software of your choice to sort, archive, and search the log files.
You can also search the forums. This questions gets asked on a weekly basis.
Specific answers require specific questions. When in doubt, post the output of "/ip address print detail", "/ip route print detail", "/interface print detail", "/ip firewall export", and an accurate network diagram.