To determine the amount of beer and wine at a party, you need to consider what kind of party you are having. You should consider the amount of people and time they will be drinking. A bottle of wine provides about 5 glasses each. You can buy beer in 6,12, or 24 packs. You may also purchase a keg that could easily provide for a whole party. I suggest a rough estimate of people to drinks you think they will have. You can use that to guide you on how much beer and wine to actually buy.