According to new rules under SEVIS, you can't go to school for degree on a F-2 visa (I am very positive about this). But it is not hard to change from F2 to F1 - you can either stay in the US and change your status through the international student office of the school that admits you, or you can go to Mexico or Canada to apply for F1 visa there. The second way is faster but might be more risky.