Ok, so you just bought an unlocked phone and you need to set up the internet configuration in order to be able to browse data with your carrier SIM Card. It is possible that once you inset the SIM Card the settings may be automatically set up. But it is also possible that it may not be an automatic thing. So if it is not an automatic thing, you will need to manually set up de Access Network Points (APN) in your phone, so that you can enable data using.
There are different carriers in the United States and each carrier uses different APN settings. So you need to locate the right information that corresponds to the carrier you are currently using. In the US there are main carriers such as AT&T, T-Mobile, Verizon and also MVNO carriers such as Straight Talk, Simple Mobile, Pure Talk, H20, just to mention the main ones.
Besides from that, the Operative System (OS) of your phone is also important because each tab may have different names when you are finding where to configurated each line. You might be using Android, iOS (iphone) or Windows Phone.
If you already read the steps on How to Set up APN settings on your phone, now you need to know which carrier you are using. Also, if you are using an MVNO (mobile virtual network operator) such as Straight Talk or H2O , you also need to know which is the main carrier they are using to provide you the service.
Here we share you a list of the carrriers with their APN Settings so you can get on the surf fast.
Main Carriers APN Settings
MVNOs APN Settings