To David:
There's a game called Dungeons and Dragons where people play as adventures and the Dungeon Master tells the story of what's happening. You can chose what class your character is like Warlock, Barbarian, Bard, or Rogue. It's not exactly like your world and there's 3 Magic Classes that sound like they could match your type of magic.
Wizards can use magic because they learn how to use it.
Sorcerers can use magic because it's in their blood and they naturally know how to use it.
Alchemists are a type of Articifer, who are generally known for creations that use magic. For Alchemists, Potions are the main type of magical creation.
Which one sounds closest to how you use magic? Wizard, Sorcerer, or Alchemist/Articifer?