You spawn in with a couple of random wands, a couple of random components, and a random perk. From there you will progress through castles full of enemies that are trying to kill you. 

Enemies drop their wand on death. Pick them up, grab the components you want and move them to your current wand. Or, if the enemy's wand is better, use it as your new main one. 

At the end of each level you'll face a boss- they're bigger, stronger, and they have a staff. Good luck.

Once you defeat the boss, you get a perk and get to go to the next level. Enemies will get more health, different kinds of wands with better stats and components will spawn.