This is a tricky one, and I may be painting myself into a corner in which case please feel free to tell me so in an answer but please also provide advice on how to get out whilst disturbing as little paint as possible!
I'm 5 sessions into a new game I've never played before and I've started fleshing out my character's background. I love detail so I'm attempting to tie it all into her class, her stats, her race, everything but I'm new to the game and I don't want to learn too much about the in game universe that will ruin surprises / locations / plot points / trivia that will likely be revealed in game (or in games to come).
For me, learning about the in game universe organically (as opposed to reading about it outside of the game) is one of the huge aspects of my enjoyments, and I don't want to spoil that.
How can I tie my character's background into a game I know little about?
I've deliberately left out the game details as I think advice could be system agnostic, and I've left out specifics of the detail I've allowed myself to learn out-of-game so far as I feel answers that give the minimum possible would be of more help to more people (who can then make their own concessions).
However, if it aids your answer: I am playing DnD5e, I've allowed myself a map of Faerün (although I am not looking up any of the places named on the map) I'm trying to tie in the loss of my orc father in a war (what war? where? I've selected a place but can I really make up my own war?) and I'm claiming I learn Dwarven and Elvish on route to find him (as a result of a chance encounter with some Elves at Location X, but what if there is no way Elves could make their way to Location X, in fact Location X's one defining characteristic is that it has never had Elves in it ever!).