The same article quotes the British security agency GCHQ (https://www.gchq.gov.uk/) on the required complexity level needed for adequate protection:
The advice from the centre is simple -- using three random words as a password should keep your information safe.
Following up on that, there are legions of sites online where you can generate random words but I think https://randomword.com/ is a rather good one because it provides some uncommon ones, along with definitions for easier memorization. Here's an example from my last access:
heterodymus
conjoined twins with two heads and torsos but one pair of legs
Memorization is optional, you could just opt for a password manager -- we have a few listed here at the forum:
- LazLock (viewtopic.php?t=23406)
- MultiPassword (viewtopic.php?t=23361)
- Keepass (viewtopic.php?t=22040)
Other related topics, mainly about password generators: