I'm on the beginners plan, And I've been buying 5gb everytime I run out. But I'll be buying in 20gb's from now on. Anyways, I want to go on to the The Next Big thing #2. But I've only had the beginners plan for a few months. Can I do this on my contract???? Will I need a better modem? (I have the one I got with the first plan).

Sorry, I'm such a newbie.