In many cultures throughout your game's world, training programs (formal or informal) are commonplace, especially for those who have not yet reached adulthood. Did your character participate in one of these training programs while they were growing up?
Training programs can take many different forms and can cover a large variety of subjects. Some of these programs may include (among others):
Music and poetry for bards,
Weapons and tactics training for warriors,
Spells and rituals for magic users,
Chemistry and technology for scientists,
History and religion for educators.
Many of these training programs may last well into your character's adulthood. But for the purposes of this prompt, try to focus on the training aspects your character encountered during their adolescence.
Like most kids, your character probably had subjects that they really enjoyed or really hated. What was it about these specific subjects that your character liked or dislike so much? How did these programs and subjects make your character feel?
Did your character choose this training program for themself? Or was it chosen for them by their parents or other authority figure? Was there a minimum time commitment associated with the training program such as with a military's term of enlistment?
These training programs help to determine your character's adult skill sets and can play a huge part in the career field(s) that they may choose when they join an adventuring party. Work with your DM/GM to see how these training programs can affect your character and your adventuring party's chances for success.