Going to drink beer and vodka for the first time?

So I'm on this superlong vacation, coming home in a week and my friends told me yesterday that they've drank for the first time and wanted to tell me about it when I got home but they couldn't wait. So when I come back I'm going to drink in m for the first time... I've had sips before but nothing more but not in a while. Then it tasted pretty bad. So I'm 15, what should I expect from coors light or bud (well see) and vodka the first time? Any tips? Thans