What gear should I have?

Hmm, guess you should start using Robes on your level. I mean, lvl 20 set. Start with chest robe and by the level, just continue to change ur armour. (the "x" means the first numer of level required)
Lvl x0 (example: 20) - armour,
Lvl x3 (example: 23) - legs,
Lvl x4 (example: 24) - wrists,
Lvl x6 (example: 26) - boots,
Lvl x1 (example: 21) - helmet,
Lvl x7 (example: 27) - manteau.

And the 2nd question... Just go to any npc vendor, like blacksmith, or tailor, take the "goods" option and press the "Repair" button to repair single part of gear, or "Repair all" to repair whole your gear.

almost every 10 lvls u should change your armor - unless is a mold one u can ware ~20 lvls
try to find 3* armors and with pdeff add-ons

I had a question to add on to your question. I'm new as well. I'm also using the sirius arcane set and the only reason I haven't switched yet is because I love the butterflies that surround you when you where the whole set together. Do you happen to know if that only works with the sirius arcane outfit? Or will that occur with any complete outfit set?
Ps- sorry for back packing on your thread, I don't know how to make my own yet. b:surrender

Ahhhh, wizards, wizzy, wiz. I love em'. Anyways, if I were you and at your lvl don't buy gear from an NPC mobs will drop them and you will get some as quest rewards. NPC gear sucks and has no benefit at all. At lvl 30, with enough reputation you will be able to get some rank gear that will last you a while. Yes low-medium level wizards are very soft. To help with that, level you're stone barrier(an excellent source of P def) as soon as you can until it's maxed and make sure you ALWAYS have it on. ALWAYS go for Phys. Def on armor or ornaments(i.e. necklace, belts) Keep your rings at the most mag att you can find. Remember a wizards best defense is their offense, so you should only get hit once maybe twice while killing a mob. Get your heal skill and cast it after every mob, and get second wind for your genie(affinity: 1 water, 1 earth, 1 wood) for when you get yourself into a hairy situation. Any other advice I can help with send me a message via core connect or post it here.

buying gear from an NPC might be acceptable, but only if:

(1) that NPC gear actually provides better stats than what you've got, AND
(2) you haven't managed to get anything better from drops or quests, AND
(3) you're somehow too poor or pressed for time to try to craft your own gear, AND
(4) there's nothing (that you can afford) in the AH that's better.

but for many, many levels around the start of the game, it's pretty far-fetched that all of those would be true at once. up through level 69, mob drops and quest rewards plus some crafted gear --- either self-crafted or bought off the AH --- should be more than enough.

(and at level 70 and up, NPC gear tends to become so inferior to all the alternatives that you really just need to stop and grind, and level up your crafting, if you can't get anything better.)