Miss Victoria's School for Girls
Forgotten Realms Campaign Setting
The game is set in the Forgotten Realms campaign setting, a rather traditional high-fantasy, pseudo-medieval setting. Forgotten Realms is the most extensively documented D&D setting of all time, first published in relation to D&D in 1987 and hosting a plethora of successful novels and video games. Your DM is struggling to refresh his own memory on this setting, so he may take huge liberties with “reality.”
All that said, you don’t need to know much about this setting unless you wish to. You’re only a teenage girl, after all, and your knowledge will be limited to what you’ve learned at Miss Victoria’s and whatever Background you choose during character creation. Everyone, including your DM, will learn about the setting together as we progress through our adventures. If you craft a background and (most importantly) take skills that would broaden your knowledge of the setting, then it will be fine for you to research these things a bit more deeply. Your DM encourages this, but he (always) reserves veto powers for any knowledge you think you have.
Miss Victoria’s School for Adventuring Girls is just outside of Berdusk. There’s also a map which shows that Berdusk is a rather large town. These pages are not 100% accurate to our current setting, but they still provide good inspiration. Your character may be from Berdusk or any of the other towns relatively nearby.
Most of our campaign takes place along the Sword Coast. You don’t need to know much about the Sword Coast unless your backstory justifies such knowledge.
The Calendar of Harptos (Forgotten Realms Wikia | wikipedia) will provide you with the Faerûnian flavor names for months and holidays and such, but ignore the info on years since we don’t yet know what year the DnD5 materials take place in.