Checking for vulnerabilities

I am aware that Linux is tested and checked a lot by the community. However, with each update or program installation, vulnerability inevitably creep when when attempting to increase functionality.

As an uninitiated and causal user (using Linux Mint as daily driver for 2y and opened the terminal about 6-8 times in all!) is there a robust way to know what the "attack surface" of most Linux distros are?

As an everyday joe, my "threat-model" is one which protects me and (my underaged child) from malicious trackers, cookies and ad servers.