You can use "I want"+infinitive in the same way as "I'd like"+infinitive in this situation, however "I'd like" is a more polite expression.
Other examples are:
I'd like to speak to Mr. Shimizu, please.
I'd like to see the menu, please.
That's a single room for two nights?
This is used to check important information, such as names and telephone numbers. When you say the sentence, remember that the intonation rises at the end.
Could you fill out this form, please?
"Could you" + infinitive is used in this expression to make a polite request. You can use "can you" in the same way, but "could you" is more polite. We use "fill in" when we have to write information on an official form.
Other examples are:
Could you repeat that, please?
Could you fill out* the membership form, please?
NB *American English
-- British English 'fill in this form please'