In the Forgotten Realms there are many major powers, each vying for power, prestige, money, resources, or all of the above. War is ever on the horizon, be it a cold war or hot all depends on a single mistep by one or more of the powers.
In this game it is the players actions that dictate what happens, be it locally or globally. Does killing a pack of wild dogs to protect your home cause an avalanching effect that causes the bandits that were being held back by the dogs to see the small home as ripe pickings? Do the bandits leaving their old hunting grounds invite in more problems in another area? Every step, or mistep has consequences, what is it that you will spark?
Though the game is sandbox there is more than a few preplanned plots, the first one is set in Waterhaven, with only clues to work from. If plots are not your thing there is still the excitement of building your character into whatever you feel you want them to be.
With no restrictions on alignment nor race (so long as it falls within the allowed sources: See Character Creation) there is no reason that you cannot play that assassin you've been dying to try, Necromantic powers your thing? Everyone needs an army behind them, why not have it be skeletal?
Just remember: Your actions dictate what happens. You may become Toril's most infamous assassin, but look what happened to Artemis...