Azure Git Portal, Branching, Commit, Push and Pull Request Issue

Azure Git Portal, Branching, Commit, Push and Pull Request Issue

I received this error. Tell me why?

Failed to push to the remote repository. See the Output window for more details.
Error encountered while pushing to the remote repository: Failed to push to the remote repository. See the Output window for more details.

Am I doing something wrong?

1. First I am checking where am I? Current branch

git branch

It shown me - I am in master branch

2. Then get lattes changes and sync my master

After that make some changes in master

3. Then I create a new local branch

git branch -c dev/myLocalBranch

3. and all pending changes was copy into new branch also
git checkout dev/myLocalBranch

4. Check again where am I? I am in new branch
git branch

5. Staging all changes

6. Commit

7. Pull

Here gives error: "Failed to push to the remote repository. See the Output window for more details. Error encountered while pushing to the remote repository: Failed to push to the remote repository. See the Output window for more details."

Why? I pushed into "myLocalBranch" only? It seems want to push into remote master?

8. Sync

Again, give me the same error.

9. I do create pull request from Azure. This mean. I saw my commits. Even it is not pushed.

10. Now in my local branch I see 1 for pushing (it is prepared for pushing). How to push in my local branch only?