1. "It is delicious, thank you!" 2. "I am paying with cash/ I am paying with a debit or credit card." 3. "Not much." "What's up?" There are many ways to answer all of these questions, but here's a few examples to get you started!

I just want to add that in casual scenarios sometimes single word sentences or very short ones are more natural. For example if someone asks "How's your food" you can just say "its great, thanks" or just say "cash" or "credit card" when they ask you how you are going to pay. But if its a more upscale restaurant you should give a little more complete answers!

1. if you like your meal, you say: " It's delicious, thank you" or just " it's very good, thank you" 2. I'm not sure I understand the question- if you give them a card, they may ask if you're paying by credit or debit. If you want to pay, just say "check please" 3. "what's up?" = "how are you?" . If you're in a casual restaurant it may mean "how can I help you?"