Dialogues

1. 我要订个比萨饼。Wǒ yào dìng gè bǐsàbǐng.
I want to order a pizza.
Nowadays with the development of modern technologies, buying things is becoming more and more convenient. For instance, you can order things by phone.
Let's say you plan to order a pizza, you can do it this way: Wo3 yao4 ding4 ge4 bi3sa4bing3.
Wo3 is I.
Yao4, want to.
ding4, to order.
ge4 is a measure word. ge4 is actually short for yi2g4, when it's used separately. means one.
Then you can also say "san1 ge4", "si4 ge4"
bi3sa4bing3, pizza.
 

2. 怎么付钱呢？Zěnme fù qián ne?
How do I make payment?
Zen3me means how.
fu4 is to pay.
qian2 means money.
fu4 qian2 is to pay for it.
ne, is particle here, it comes at the end of the sentence.
　

3. 可以货到付款。Kěyǐ huòdào fùkuǎn.
You can just pay on delivery.
They may suggest you pay online or via the post office. But I'd say it's better to pay on delivery. I mean in that way you can first check the quality of the product and after that you can make payment.
For that you can say: Ke3yi3 huo4 dao4 fu4kuan3. You can just pay on delivery.
Ke3yi3 means can.
huo4 means product.
dao4, arrive.
fu4 is to pay.
Kuan3 means sum of money.
fu4 kuan3 is to make payment.

4. 你说一个时间。Nǐ shuō yí gè shíjiān.
You name a time.
Ni3, you.
shuo1, to speak.
yi2 ge4, one.
shi4jian1, time.