I don't like root beer much and so the thought of root beer + the ethanol bite that comes with any strong spirit is rather sickening.
As much as I could go out my way to recommend various brands of scotch, bourbon, Irish whiskey, tequila, pisco, etc. I think that if you've made it to legal drinking age having had nothing but vodka, you should enjoy the variety accessible to you and try a bit of everything.
Tell your friends to take you out to a nice bar and have each of them buy you a drink. Pace yourself and try a glass of scotch on the rocks, a shot of bourbon, a gin fizz (alternately a gin martini), a pisco sour, and a Dark and Stormy (rum, traditionally Gosling's Black Seal, mixed with ginger beer). Tell the bartender that you're inexperienced and want a wide variety of delicious beverages. Leave the choice of brand in his/her hands (this is why it should be a nice bar- you don't want to get served Malibu and gutrot).