Get is a very important word in English because it is used a lot by everyone.  It has 5 different meanings.

1st:  Get means receive, obtain or buy.  It is followed by a noun (the thing received, obtained or bought.)

Examples:
The boy got a new bicycle on his birthday.
I would like to get an A on the next test.
She gets an email from him every day.

2nd:  Get means become.  It is followed by an adjective.

Examples:
She got sick after eating the fish.
The children may get lost if they go by themselves.
They got married last weekend.

3rd:  Get means arrive.  It is followed by a place.

Examples:
What time did you get home last night?
I got to school early this morning.
We’ll get there as soon as we can.

4th:  Get means bring and give.  It is followed by a person and then a noun.

Examples:
I got her something to read while she was in the hospital.
We got you two tickets to the concert this weekend.
Did you get me a bicycle for my birthday?

5th:  Get means possess (to have something.)  It is used with have and is followed by a noun.

Examples:
I’ve got three sisters.
She’s got plenty of time to help us.
We’ve got mice in the attic.

Note:  In informal English, speakers often drop ‘ve [but not ‘s]

I got three sisters.
We got mice in the attic.

6th:  Get means understand.  It is used informally and is followed by a noun (the thing that was understood)

Examples:
I still don’t get his decision to drop out of school.
Did you get what he was trying to say?
That joke was so stupid.  I didn’t get it.

7th:  Get means deal with (give your attention to.)  It is followed by a noun (the thing that needs to be dealt with.)

Examples:
There’s someone at the door.  I’ll get it.
Could you get the phone, please?  I’m busy.
You answer that email, and I’ll get dinner.

In addition to these 7 meanings of get, there are lots of idioms with this word.  Here are some.

get in – enter (a car, a truck, bed)
I got in his car, and we went for a drive.

get out of – leave, exit (a car, a truck, bed)
Get out of my house!

get out of here – I don’t believe you
You won the lottery?  Get out of here!

get on – enter (a bus, plane, train, boat)
We can get on the bus across the street.

get off – exit (a bus, plane, train, boat)
After they got off the plane, they took a taxi downtown.

get up – arise
It’s time to get up now.

get down to – start working on
We should get down to work soon.

get back – arrive back home
What time did you get back last night?

get by – have just enough
They don’t have a lot of money, but they get by.

get around to – start to do
I’m tired now.  I’ll get around to that job later.

get over – recover from a sickness or sadness
It took her two weeks to get over her last cold.

get through – to finish something unpleasant
Don’t worry.  I’ll help you get through this.

get together – to meet someone
Let’s get together after work for coffee.

get in touch – to communicate
I have to get in touch with my brother.

get rid of – to throw away
I think you should get rid of that terrible painting.

get along – have a good relationship
My sister and I get along very well.

get on (one’s) nerves – bother (one) a lot
Sometimes my children get on my nerves.

get (one) down – make (one) sad
Bad news always gets me down.

get ahead – be  more successful
If I don’t graduate, I’ll never get ahead.

get away – escape
She helped her sister get away from her bad husband.