Major, welcome to the BBF.
It doesn't matter that it from another carrier as long as it has been unlocked to work on your new carrier. How do I unlock my BlackBerry? - BlackBerryFAQ
If yours is working, it is unlocked.
Make sure you have a BlackBerry Data Plan on your account, also.
Follow these tips to get your browser if all of the above is true: Internet Browser FAQ - BlackBerryFAQ