Guardians are set up to have no back story, by having no memories when they revive, and be an insert character. It's why the guardian rarely speaks. Destiny handles players in lore, as every player is A guardian, and you are THE guardian. This basically means no, not at all. Your guardian was made for you to give them whatever story you want and more or less be the guardian. Even my guardian has lore, and I'm mostly a trials junky these days.