[MM3-users] First time mailman installation

I have installed mailman3 on Ubuntu including postorius & hyperkitty (from the packages).

I have questions now which are not quite clear to me from the docs:

1. How do I specify my mail server details (which is my own server running postfix, etc)

2. How do I create new lists from the postorius UI, or can I only do that in the config files or the command line console for mailman3?

thanks!