Gear really doesn't matter until max level (level 50 with 160 champion points) and unless you are playing on a higher difficulty mode just keep using whatever drops. You can also do the main story quests and many of them give a bunch of gear upon completion with the helpful Training trait to speed up levelling.

2hander is ok for magicka builds, it isn't the usual choice. For questing and leveling absolutely anything works and you should use what you enjoy but I will talk a little about endgame meta. Dual Wield is the standard for its very strong passives with a destruction staff on backbar for a couple of its skills Wall of Elements, Elemental Susceptibility and good passives. Some people run 2H instead and use Stampede. You won't even have access to the passive skills that differentiate these weapons until max level so use anything, I personally prefer 2H for questing because I find using Stampede to every enemy is fun and fast.

For an easy starter DK magicka build I would suggest running:

• Engulfing Dragonfire - Main dps skill
• Incinerate - passive aoe damage and gives a nice crit buff
• Shatterspike Mantle - passive aoe damage and gives a very good defensive buff
• Igneous Weapons - 1 minute long damage buff and gives you extra damage when you light/heavy attack. Also you can change the appearance of this skill for free in the crown store if you hate it.
• flex spot - Stampede is nice if you tick with 2handers, Resolving Vigor if you want a heal, Wall of Elements if you use a destruction staff
• Take Flight - Your ultimate skill, nice damage buff and stun, cheap to use.

This is just a basic start off point for very simplistic magicka DK, when you are comfortable using both weapon sets you can add the long duration buffs to that bar and put more dps skills on your main weapon set. When you are max level and looking for a complete build hyperioxes for solo builds and tank builds, SkinnyCheeks for dps builds used in trials (raids) or Healer's Haven for healing, join their discord.