Setup sys-firewall and rename my hostname


I would like to know how could I setup my sys-firewall to offer wifi to my qubes, and not to communicate with others machines on the same wifi, i’m not familiar with public wifi but I will need to use one while on trip, so i’m looking to protect myself much possible from possibles attacks.

Also, to stay anonymous, I would like to know what do the wifi will see from my machine? I saw peoples saying that the ISP & other users will just see my hostname, but I doesn’t know what is my hostname. Anyway about how to see it and change it? Also, would it be possible to setup an non-persistent hostname to avoid tracking?