If you haven't really worked out what Aspects are yet, maybe start by reading this guide to Aspects in Diablo 4. Psst, don't be embarrassed if you haven't worked out how to switch weapons yet: The type of weapon doesn't really matter, what matters is that you use weapons with these affixes (and in this order of priority) :

You can use the following gear as a Necromancer: One-Handed Swords, Daggers, Wands, Focuses, Shields, and Scythes. We're hoping they buff the undead minions in an upcoming patch.

Even by the midgame you will require a lot of corpses for resummoning undead minions, so don't waste them!

Skills that require corpses, like Corpse Explosion, are great in the earlygame, but you want to move away from them as you get deeper into the game.

You can let beefy characters aggro the boss, and the Rogue can dish out single-target damage.

In group-play you can be most useful to your party if you focus on the mobs.

These summons will die, rarely at first but far more easily as you get deeper into the game.

So when you come up against harder content as a Necromancer, don't be fooled by the false sense of security your skeleboys provide. Necromancers have decent survivability but they aren't Barbarians and they don't have any evasion skills.Necromancers have loads of awesome things going for them, but you should also be aware of their shortcomings: We'll start with a very brief intro to the Necromancer.

Diablo 4 necromancer release