GitHub has limited plans where you can't make private repositories, it's used to work with open source platforms, If you are working for your project I would recommend you to take a look at https://bitbucket.org/ you can make unlimited private repos for free with 5 users.
GIT is better at control version even you create new branches as features before to merge master version. You can learn this, It's very easy.
http://rogerdudler.github.io/git-guide/
I use GIT a lot to manage a project with different features and had 0 conflicts