One of the best ways to learn English is to learn answers to common phrases that you will hear all the time.

So let's pretend today you go into a coffee shop and the person at the counter says to you, "What can I getcha?"

What can I getcha?

This means "What can I get for you?"

What would you like to drink?

What would you say to him?

Let's pretend you want a green tea. What could you say?

Three common ways you could ask for a green tea are "Could I have a green tea, please?"

Could I have a green tea, please?

I'd like a green tea, please.

Or "I'll have a green tea, please."

I'll have a green tea, please.

These are all very polite phrases to ask for something or to order something at a restaurant or a cafe.