“I’d like a slice of pizza.” – A slice means a single piece of pizza.
“Can I have extra cheese on my pizza?”
“I’d like a meat-lovers pizza.” – A meat-lovers pizza usually has all of the kinds of meat that the restaurant serves. Usually pepperoni, sausage, Canadian bacon and hamburger.
“Do you have any specials today?” – A special is a meal that is cheaper than normal. The pizza parlor I go to has a lunch special where you get 2 slices of pizza and a soft drink for $6.
“What toppings would you like on your pizza?” – This is what the waitress might ask you in order to find out what you’d like on top of your pizza.
“Thin crust, hand tossed or pan?” – Lots of restaurants have different types of crusts. Pan can sometimes be called thick crust.
Here’s a typical dialog. You will be the customer and say what you’d like to order:
Waitress: May I take your order?
Waitress: What kind of crust would you like? We have thin or thick crusts.
Waitress: And which toppings would you like?
Waitress: Is there anything else you’d like? Something to drink?
Waitress: Great, it will be about 10 minutes. I’ll bring your drink right over.