I understand you want to jump right in and play necro and it probably would be painful, but at the same time it could be fruitful if you can manage to stick it out.

If you're interested, an alternative that might be really helpful, would be to roll a class with good melee and defenses, like an assassin, or good support, like a bard, whose role is something along the lines of they absolutely love necromancers but couldn't be one them self for what ever reason you want to come up with. Then talk to every necromancer you see and tell them you love their work and offer your services to them.

My guess is you'd find a bunch of necro's willing to take on an ally who would be useful to them in doing their necro things (like raising armies) because of their melee or support capabilities and let you tag along with them.

This way you'd get to see how a variety of players play the class and learn the ins and outs of it by watching without having to suffer through the learning pains of CF and the class at the same time.