DO NOT buy Four Loko.
That's about the WORST suggestion for a first time alcoholic beverage, positively LOADED with caffeine so that your body won't know what's going on and you'll be racy as hell and drunk at the same time and feel HORRIBLE afterwards.
If it is your first time drinking I would not even suggest hard liquor like vodka but if you have to don't exceed like maybe 4 shots within a bout 2 hours. I'd start with maybe 2 shots....wait about 45 mins, and have another.
Or you could mix yourself a screwdriver with orange juice and about 4 shots of vodka and SLOWLY sip it for an hour or so.
Better than that is to buy yourself a six pack of some average strength beer like Sam Adams or Saranac or even just some budweiser and just have a few and progress to the hard liquor some other day when you know how alcohol effects you.
Stay hydrated, drink a lot of water and also buy yourself a gatorade and drink that for electroylytes.
If you've never drank in your life it's probably about time that you'd be interested in trying something other than weed, so why not try something different?
Just stay safe and you might be hung over and need something for a headache next day.
DON'T have ANY Tylenol in your system while drinking, and DON'T drink really fast.
Have fun.