Docker error when running first container

Hey guys, this is my first time trying to use Docker so I apologize if this is an easy fix. Anyways, here are the following:

[8] System error: exec format error

I’m using ubuntu 14

Docker version 1.6.2

So I created a directory, called Dockerfile and created a new file called Dockerfile. In there I had the two lines of code:

FROM alpine

CMD [“echo”, “hello world!”]

I would build by:

docker build .

and then run with:

docker run --name test (docker container ID).

and then that’s when I get that error, does anybody know why?

The command is

docker run [OPTIONS] IMAGE

There is no container you can address at this place. To give the image a name that is easy to remember you can use the -t or --tag option when you build it.
Then be aware of this: Your container just echoes ‘hello world’, after that it has nothing to do, so it will be stopped immediately.