Before we can answer this, it might help to know what your current favorite and least favorite school is.
Here are some generalities to help you narrow down your choice.
Ice is best at defense, surviving long battles by using shields & slowly eating away at the enemy. They don't do much damage in the first Arc but really come into their own after level 40. By level 50 or so, they can dominate in PVP. They do struggle with accuracy by level 40, whereas Storm & Fire get boosts that put them near perfect accuracy. Ice can work well soloing, or as a tank on a team. They don't have innate healing, so consider training in Life as a 2nd school.
Myth is best at working with various minions. They can summon help into battles over & over. A major drawback is that Myth doesn't get any good AoE spells & will have to learn to pick off the weakest enemy first. Battles will take longer. Myth does have the ability to remove shields, blades, traps, everything the enemy might use to buff & defend themselves, making them good candidates for team play. In PVP Myth seems to struggle somewhat. And by the end of the game, Myth is a rare sight. Consider training Life so you can heal your minions & survive the longer battles you will face.
Balance is an all-purpose utility school that does best with team play. Their spells are all over the place, some using strict Balance & others splitting the damage between multiple schools. Breaking shields is fairly easy for them. They have AoEs, but the AoE spells are relatively weak until Nested Fury (level 108). They have a hard time concentrating their own damage into one hit but are great at buffing other schools. Balance has their own heal spells (2 of them), so training Life is optional. They do well in PVP.
I've played all the schools & have to admit, Myth was hardest (it was my very first), then Ice ... until she hit level 38 & got her 40% blade. After 40, Ice was easy.
You could just play all three through wizard city or even krok and decide which one you like best. It will only give you a small sample of what you can do, but if you hate one of them early on, it will be a long road until their high enough to where you may like them.
Balance was my first wizard. I adore playing her. You'll be doing a lot of support though. That's what the school does best. I am not geared out to do a lot of damage, so fights can be very long, especially playing a balance boss or mob. You don't have anything good to break through the resist, so you're best spells can't be used, until you hit Polaris and get the Nested Fury spell. I can tell you a mob of all balance could get very annoying when all you have is elemental blast. Balance are pretty good survivors and decent soloers since you have a decent amount of health, good accuracy, and your own heals.
My ice is only level 41 since my sister doesn't play as often and I play 4 of my wizards with her, so I can't comment much. Ice is pretty rough in the low levels because you don't get your school blade for a long time! You can get by this with getting the treasure card, but your damage is going to be pretty low. Everyone says you never die on ice, but I think that's more in the higher levels after your stats get better and you have the right spells.
I personally left Myth out, but that was because when it came to my last school and my sister's last school, I let her pick. She chose myth, so that left me with ice. They really need that 7th slot because I really really want them all. I can't afford another account, but there are many of us who could drop $10 or $20 to say, unlock a 7th slot. *hint hint again ki*
Alia Misthaven