What's the best way to answer a question about the Firewall/AV security testing?

Hi everyone, i've just been hired as a cybersec apprentice in a company. Soon i'll have to take another internal interview and i've been asked to prepare myself at best on some topics.

It is very likely that one of the questions will be: "How would you test the security of a firewall/AV/IDS?". I haven't found a "correct" answer yet (since i can't find a standard procedure online) but what's the best way i can answer to this?

av cybersecurity firewall security security testing testing