New Player Tips
Character Creation - Class selection just gives you some initial abilities, you can freely choose any abilities you want later on so don't worry about it.
Buying Skills - Each skill that you buy raises the cost of all other skills. You will eventually be able to afford all of them however.
Group skill passives - Each skill has one or two types. When you have the same types on your skill bar you gain passive bonuses. You can view these passive bonuses and what ones you have by hovering over your skills in the skill menu.
Transmutation - In the arcanist building click the 3 horizontal line button to see the transmutation recipes you can use. They allow you to customize your gear and multiple useful ways.
Dismantle items - Dismantle all items rather than selling them. Oftentimes the dismantled resources can sell for more than the item, that is if you don't want to use them to craft and transmute things which is what you will be doing a lot too.
Eatery for xp buffs - Check out the eatery for XP buffs. These will help you level much faster. After each area the eatery will refresh with new food. Reliquary items also increase faster with XP so those make it even more important to get XP buffs.
Black Market - You have to pay gold to refresh the black market. It will usually have blue and purple recipes / gear. It does not contain legendaries. It shows no items until you pay gold to refresh it.
Forging - You can upgrade gear 5 times using forging in the craftsman building. I would wait for purple / legendary gear to use this on. Note you can switch stats and improve the quality of items after they are forged so if you have a purple or legendary you like you can feel safe to forge it early on.
Patrols to get specific ingredients - Different patrols provide higher chances to get different crafting ingredients. For example the mine patrol often gives ore which is used in heavy armor.
Making Gold - The primary way to make gold is by selling the crafting resources generated from dismantling gear. You should always keep the high end orbs, but sell the basic crafting resources for gold sometimes.