When you connect to a router or wifi you are assigned an ip address so that the information you request from the internet knows where to go. It is usually assigned dynamically (or different every time) so that a device i.e. your phone can connect without interfering with something else This allows many things to connect seamlessly. However you can set a static configuration which means that it doesn't request one to be assigned by the router, but rather uses predefined settings that you set. The problem with that, especially on a phone, is that if you go to another place and try to connect you can run into issues while connecting. It is best to leave the static information alone unless it already has stuff in there, which should be deleted. If you don't have a reason to set a static ip address you shouldn't use it.
Metro PCS Easy Wifi merely connects you to certain networks automatically if you are within range of them. Thousands actually. If you are at home or work though and not within range it won't help you.
You don't need to root your phone to get online although it can be a very helpful thing if used properly.
I think that the issue you're experiencing is that the wifi network that you were connecting to before is no longer available or now has a password, correct?
The only way around that is to find someone that is willing to share their password with you or get your own internet connection.
