3 - Phrasal verbs ( check out, go off )

check out

The police check out your luggage ? (You would not use a phrasal verb here.)

Did the police check your luggage?
it before send the stuff, Please, check out all stuff. (You would not use a phrasal verb here.)

Before sending the stuff, please check everything.

ir before parking your car, check out is allowed to park. (you would check out when you leave, not when you enter)

Check out is required before leaving the parking lot.
The enginner will check out the project. (This is correct)

go off

I'm going off my car.

I'm going off to my car.

The man is going off the store. (You would not use a phrasal verb here)

I saw the police going out of the police station

I will go off to my country tomorrow after lunch.

Other examples:

I heard the alarm go off.

The girl got angry and went off on me. (meaning yelling)

3 - Phrasal verbs ( check out, go off )

Primeiro, se voce quer dizer emprestar um livro da biblioteca.

Example: I am going to check out a book from the library. 

Segundo, dar uma olhada em alguma coisa.

Ex: I am going to check the movie out since you told me it was really good. 

I am going to check out this new restaurant in town.

Pode ser tambem de um sentido promiscuous.

Ex: Hey check that guy out. He's hot.

Terceiro, said de um hotel...do sentido que vc vai devolver as chaves e deixar o hotel 

Example: I need to check out of the hotel by 2:00 p.m.

The police check out your luggage ? Did the police check your luggage? Check out is wrong to use because it implies that the police is looking at the object sexually or promiscuously...
it before send the stuff, Please, check out all stuff. 

Before sending the stuff, please check if you have all that you need.

ir before parking your car, check out is allowed to park.

Before parking your car, check if parking is allowed. 
The enginner will check out project.

Good...except enginner - is spelled engineer. 

go off

Primeiro sentido e que alguma coisa para de funcionar ou ativar...

The alarms go off at night.

The lights go off automatically when the office is empty.

Segundo pode dizer basear  em alguma coisa

You can't go off what she says and bas your decisions like that.

I'm going off my car. I am going to my car. 
The man is going off the store. I am going to the store. 
I saw the police going out of the police station. 
I go off my country tomorrow later of my lunch. doesn't make sense.