There is more to it and all spoilers.
“I’m too young to die!”
“I’m not, but I still don’t wanna.” 
By that look of pure joy on her face I don’t think calling her evil is much of a spoiler.
OK, then. I guess I’ll withhold my judgment for now.
Yeah, not so much. She didn’t strike me as a nice person. 
Don’t be such a big baby! You can tell by the look on her face that she’s an evil witch–that’s just Azula’s style. That’s how she rolls!
That is another great thing about this show. Since it has a specific beginning and end you can assume that most if not all of the big questions will be answered at some point.
Yes, Uchiha is right about there being much more to the Fire Nation attacking in the first place. You’ll learn more, but you don’t fully learn the whole thing until the end of the 3rd season. Well worth the wait though.