I suggest quitting immediately, purging your cache, and never speaking of this atrocity again.
What's the deal?
If I don't buy a class armor right away is there a penalty? Meaning will I lose the chance to gain class levels: for example if I had bought class armor at level ten instead of level fifteen, would I have had 5 more class levels?
Right now I'm level 10 or so and I'm not sure what class I want to be at this point...Should I decide earlier rather than later?
As to whats the deal? Some people don't like for any number of reasons, and some people prefer other flash games that I don't like. Regardless, AQ is worth a fair shake IMHO, it might be just what you need to fill a few spaces of time.
As to the other part. No penalty for waiting. But, you can take ALL the classes, the only thing that differentiates the characters is how the train their stats, not what class they take. You just equip the armor of the class you want to use at the moment and can even switch classes by switching armor in the middle of a fight. So...no reason not to just pick one and start working on em=) You don't lose your class levels if you sell the armor either, you just have to repurchase the armor to use the skills again.