You have to have an online pass to access stuff like online franchise, you may have lucked out and gotten a used one but odds are you'll have to purchase one before you can move forward. Its $10 or 800 MSP (the point is to encourage purchasing new as opposed to used). You're still managing to save money if you have to purchase the pass (M11 is $30 new, your purchase even with the pass would cost $25).
I believe that NCAA 11 ceased their support for its online dynasties with the release of NCAA 12 so I'd check to make sure that there is still support for online franchises before spending the money on the online pass. Hopefully they are still supporting online franchises and hopefully you were lucky enough to get a copy with the online pass unused. Good luck