Online classes are not easy. When you first sign up it seems as if you'll have all the time in the world to prepare, and then, suddenly, it seems as if the class is about to end and you have done absolutely NOTHING!
Attending classes online requires a lot of self discipline, which simply means that you have to treat the only classes as if they are real classes. Set several times a week that is allotted specifically to doing assignments. In fact, if you think you'll only need to spend 3 hours a week for a class, give yourself 4 hours a week. This will allow you room for error and maybe even give you the ability to finish early.
It certainly is no easy task, as it takes a special kind of person. But I think anyone who is capable of writing consistently on HubPages, journaling, regularly, or doing any other task that requires commitment, should be fine in an online school.
Try taking just one class to see if you have what it takes. If that is a breeze, then you can start taking fuller semesters.