In The Dragon Prince, there are some people who are well-trained in magic, such as Claudia and Viren, and others who don't know how to do it.
Callum notes that he wasn't taught to use magic, and expressed surprise when he successfully cast the aspiro wind spell. Rayla was especially impressed with this, saying that she didn't know that he was a mage.
Is being a mage and being able to cast spells an innate talent that only some people have the gift to do (similar to element bending in Avatar: The Last Airbender)? Or can anybody do it with the proper training?