Commands used:

 git config user.name "MyUserName"
 git config user.email "***@example.com"
 mkdir gitrep

After moving to gitrep:

 git init
 touch readme
 git commit -m "first commit"
 git remote add origin https://github.com/<Username>/gitrep.git.

After this command, I created a gitrep repository in the website.Then I typed this:

 git push -u origin master

My file got uploaded to github with the following output:

 Username for 'https://github.com': Sang12-2017-18
 Password for 'https://<MyUsername>@github.com': 
  Counting objects: 3, done.
 Writing objects: 100% (3/3), 217 bytes | 0 bytes/s, done.
 Total 3 (delta 0), reused 0 (delta 0)
 To https://github.com/<MyUserName>/gitrep.git
 * [new branch]      master -> master
 Branch master set up to track remote branch master from origin.

I can now operate github from terminal!