We can use get and have in both active and passive patterns.

• The active pattern, meaning 'cause or order someone to do something', is get + person + to-infinitive, or have + person + infinitive without to:

I'll get the waiter to bring you the menu.
I'll have the waiter bring you the menu.

Note that have is much more common in American English; get is common in spoken British English.

• The passive pattern, meaning 'arrange for somebody else to do something', is get / have + object + past participle:

I'll have / get the menu brought to you.
I had to get / have my jacket cleaned after the party.
I must go and get / have my photo taken for my new passport.
I'll get / have those copies made for you immediately.
She's getting / having her teeth fixed.

We can sometimes use get instead of be in the passive. This is usually informal:

They got punished by the Principal for making so much noise.
Lucky Paul got promoted / elected / chosen / appointed yesterday.
Poor Vassili - his dog got run over last night.

• Get meaning 'become' is also common with a particular small group of past participles:
get dressed * get married  * get used to * get stuck * get lost * get caught * get burned * get involved

• The meaning of these phrases can be active:

I got dressed as quickly as I could.

• We can use some of these active phrases with an object:

I have to get the children dressed early every morning.
Don't get your family involved in the business.

We use have + object + past participle to describe things that happen to us, often misfortunes. The subject is the person who experiences what happened:

I've had my car stolen. (Compare: My car was stolen.)
He's had his application for citizenship turned down. (Compare: His application for citizenship has been turned down.)
My mother's had her letter published in The Times. (Compare: My mother's letter has been published in The Times.)

• In spoken English we can sometimes use get instead of have:

She's got another letter published in The Times.

• Note that sometimes only the context will identify precise meaning. Consider:

They had their fence pulled down. (= either: they employed somebody to pull it down (causative); or it was pulled down without their planning it, e.g. by vandals.)