Hi, after you do some of " A Gaurdian Rises " the first new light quest; you should get another quest called... Riding The Storm That unlocks your arc subclass, after that your other classes are available. When I say available though you may have to pay in glimmer to unlock a lot of the fragments & grenades etc... If that still the case just a tip... 1) I would unlock void first because it's easier to survive 2) unlock the fragments that give you stats first... like + 10 resilance, recovery etc... If you have questions feel free to ask. Cheers