How do I use Firewalld?

[arky217]

In LL4.8, the ufw firewall was simple to operate, just set it to autostart on boot.

In LL5.0, Firewalld seems very complicated.
I can't figure how to make it start at boot and the options are,
at least to me, not understandable.

Also, what is Firewall-cmd and how does it figure into Firewalld ?

Is it ok to just use the default Firewalld settings ?

And how do you start Firewalld and how do you autostart it on boot ?

And once you have it running, how do you disable it if needed and
then re-enable it ?