Vlad is the pivotal member of this team.
use git checkout -b "mybranchname"
to create your own branch.
also git push -u origin "mybranchname"
to push your branch to github.
To commit your local changes
git add <file>
git commit -m "message"
To push those changes
git push
To merge your changes into master assuming you've pushed all of your changes to your own branch
git checkout master
git pull
git merge <my local branch>
At this point we may have merge conflicts
We will resolve all of them and then commit changes
git commit
Now we push those changes back up to master
git push
And switch back to our branch
git checkout <local branch>