How do i get more thaumaturgy powers?

[Deathjester]

I've been using the force push and it's been great, however i want the ability to turn enemies berserk, how do i do that? Or Necromancy? I'm confused

[winterline]

At the start you can only learn confusion, calm or torrent, as soon as you can start learning a new skill you can then choose a skill that is needed for spells, mind tree is what you want, hover over the spells to see what it is and what is needed.

[Flyin' High]

First of all you'll want to press P (or whatever you have your "Power Tree" bound to) to open up a menu, from here you'll see a menu where you can unlock new powers, hover over a power to get it's name and a vague description of what it does.
Quite important to note the wheel at the bottom left, which has 6 categories of thaumaturgy, Mind, Force, Body, Energy, Light, and Displacement, only Mind and Force are actually implemented though. Force focuses more on pushing characters or objects, while Mind focuses more on controlling emotional states and getting minions.

Left click on one to start unlocking it, much like how you level up, you can only get the power AFTER it's done unlocking. Click and drag it to your hotbar at the top to prepare them for use.
Some powers require certain skills like Inversion or Continuity to unlock, most of the skills required will be in your Insight tab in your skill menu (press K or whatever you have bound for "Skills"), while Continuity and more "practical" skills will be in Concentration.

Generally everything in Insight is for unlocking new powers and Concentration is for actually improving your ability to use Thaumaturgy, with continuity being both used for unlocking more skills and also being useful in increasing how much you can actually use certain ones as well.