What you need to do to organize a buffet party at your home is to arrange a large table with all the dishes set on it. You need not to serve the guests, as they will have it on their own. Alongside the dishes arrange plates, knives, forks and glasses.
It is better to assign tasks to others to have everything just under control. For instance, someone serves the drinks, or someone stands at the door to receive the guests etc.
If it is a big buffet party, you can use paper plates and disposable spoons, knives and forks to avoid dishwashing.
Make this thing clear to the guests beforehand if the buffet is a meal or just a nibbles.
Make certain where you want to serve drinks, in kitchen, in living room or in a hall. Living room would be a good option.