It can vary a lot from person to person, I'd space your shots out so you don't end up too drunk - too drunk can be very unpleasant! 250ml of whiskey is a
lot for your first time especially as you don't know how your body will handle alcohol, I really wouldn't drink all of it.. Make sure you've eaten well and aren't drinking on an empty stomach too to minimise the chance of getting too drunk too quick (honest, I know you want to get drunk, but you really don't want to do it too fast) or throwing up. The most fun part of being drunk IMO is the early-mid stages, it just goes downhill after there..Be careful too, you don't want to go to far and end up passed out, or losing your inhibitions and doing something dangerous etc..
Drink plenty of water before you go to sleep too, you'll thank me tomorrow