Root is the Linux term for administrator or super user. It's telling you that when you are logged in as a regular user, you don't have administrator privileges, so you can't change system settings. In order to do that, you have to click the option at the login prompt to set an administrator (root) password. But you shouldn't be using Tails as the administrator. You should do normal activities as the regular user. The fact that root has no password set when you log in as a regular user is a security feature, because an attacker can't get root privileges on Tails by guessing a password. He would have to exploit a privilege escalation bug, which may be considerably harder. I'm not sure. It sounds like the Linux driver for your wireless card is buggy. I recommend buying a cheap wifi dongle that works well with Linux. You can search the reviews on a site like Newegg for the key word "Linux" and see what other people have to say. You can find wifi dongles that work excellent on Linux for like $10-15.