Fireball does hit in an area. If you are coming from PoE, it's important to note that the flat fireball hit damage doesn't affect the ignite power.
I think you'll find that you probably want to use a different weapon as a sorc, probably a staff or wand/catalyst.
It sounds like you might be a newer player which is a great place to be starting 0.9 at I think.
The best advice I can give for this is to use what you find and just improve your gear and build as you go.
Some general advice I can give is that you'll want more health, 100% Crit avoidance and 75 all res as a baseline for end game defenses. If you primary goal is ignite fireball, look for increased fire damage, increased spell damage or increased DoT damage affixes.