I just saw checked your command list and saw that you actualy forget to start the service (at least this would have happend if docker was installed correct). I did not check your logs as your commands tell what you did - at least this is what I thought. Your log indicate that you skipped steps!
The pgp key is missing. Your logs do not include all the steps your command list has:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88
There is no trace of this commands beeing executed.
. Why didn’t you just use the convenience script that does the setup for you?
$ curl -fsSL https://get.docker.com -o get-docker.sh
$ sudo sh get-docker.sh