Learn a Spell
Studying with a teacher or magical text adds an entirely new spell to a caster's repertoire, provided the tradition and skill line up.
Concentrate Exploration
You can gain access to a new spell of your tradition from someone who knows that spell or from magical writing like a spellbook or scroll. If you can cast spells of multiple traditions, you can Learn a Spell of any of those traditions, but you must use the corresponding skill to do so. For example, if you were a cleric with the bard multiclass archetype, you couldn't use Religion to add an occult spell to your bardic spell repertoire.
To learn the spell, you must do the following:
Requirements You have a spellcasting class feature, and the spell you want to learn is on your magical tradition's spell list