i don't understand this "drink alcopops - they won't do anything to you".
Of course they will! Most Alcopops are just as strong as beer (4-5%) and much easier to drink, you will drink faster, it will be easier to drink more and you are more likely to get drunk. Additionaly the high sugar content will probably make you quite excitable.
I would say the best drink would be a weak, pale lager such as Fosters or Carling. If you like it, because being in pints you can sit there sipping it for hours and no-one is gonna question your drinking rate. For someone thats never drunk before you will feel the effects after about 1 pint. (poss less, depending).
Mixing drinks (such as wine then beer) in any quantity is much more likely to make you sick, so not somehting i would reccomend for a first time.
Anyway, only drink if you feel comfortable with your surroundings and the people there. Keep your phone on you to ring home and make sure you know how your getting back/ where your sleeping.