What OddFiction said is right. Ordering a pizza by yourself is very straightforward, and the small talk is minimal, often nothing beyond "hi", "have a nice day", and maybe a "how are you" at the beginning. If it helps, have the information they need written down and/or circled on the menu. Then rattle it off as they ask for it. If they offer an add-on or a special, it's simply a sales pitch they're trained to do, and you have every right to decline. At the end, I usually like to repeat my order and my address back to them, to make sure they have the right information. No one ever had a problem with it.
On the other hand, ordering pizzas for a groups of friends makes high school gym look tame in comparison, and that does 100 times if they're drunk and 1000 times if they're stoned. You're trying to enunciate the order, while people in the room are telling what they want, then when you're about to close the conversation and get a price, one person decides he wants more toppings, then when you finally tell the order taker, he goes back to his original order, then another person decides he wants cheese fries instead of crazy bread, until finally, you tell the order taker "I'm sorry, I'm going call back", hang up, and barely restrain yourself from smashing everything in the room while everyone is laughing at you, and vow to never host another party again.