Ok, so I am a level 44 wizard, and I have horrible gear and am a bit underleveled. I am already near celestia, currently in the forum, and I was wondering a couple things. First, my gear. I want either zues or senetors gear, but the first time I did mount Olympus, I got nothing, and it was a struggle, and I feel like it would take foreverrrrrr for me to get death gear if I tried farming that. If I was gonna do that, I would need a max level to help me. If you have any suggestions on other gear to wear or if you could help me with Olympus, please comment. Next, my level. I want to have my level 48 spell (crow), by the time I get to celestia. So if you could tell me any way to level up fast, please tell me.
Now that you're a higher level, Olympus shouldn't be so hard. If you still can't solo it, try team up - going in with even one more person will make the whole experience much more pleasant for you.
Gear - If anything, farming usually nets you the best gear. It took me a few days of farming Mount Olympus to finally get the 3 Zeus' pieces. That's what I would suggest. You can use the team up button if you're having trouble finding people. If you're big on crafting, once you reach 56 I believe you can craft the Wintertusk gear that will last until you can farm Waterworks.
Sky Iron Hasta, a wand that drops from Mount Olympus, I believe is a guaranteed drop, it gives +1 power pip and +10% damage, so it's an ideal wand to have for that level.
For the athame and ring I usually go for power pip chance and healing over health and mana. I can manage fairly easily, but I have to stop for mana pretty often. This is largely up to preference until you can get Lexicon Blade and Aureate Band from the Tower of the Helephant.
The deck isn't that difficult, use the deck that allows you the most spells of your school type to allow for more dynamic deck set-ups.
Level - Usually becoming under-leveled happens when you don't do side-quests. Doing every side-quest in every world will allow you to be an appropriate level for the next. If you find the time/help, you can also do Grizzleheim. Grizzleheim itself doesn't really give that much EXP (I went through the entire world at level 50 and didn't level up once). There are very few side-quests and doesn't take much time to complete (~3-5 hours on average for me). While Grizzleheim doesn't prove to give much EXP, once you have access to Wintertusk, the EXP you get is enormous. After completing only a quarter of Wintertusk I was able to get to level 56 before completing half of Dragonspyre. I have to warn you though, Wintertusk can be incredibly difficult at level 50 and I would suggest trying to find someone to help you out.