I installed magento on my ubuntu local machine, and I connected that to github, when I make changes to the magento CMS for example, on my local machine I changed the content of the home page, I expected to see the differences by running a git status, but no differences shows up, and when I push the magento to git, still the changes I have made don't show up. At the beginning I initialized the git and I have added the entire content of the directory to the repository, there's no git ignore files or any missing files. What can I do?
When you say "when I make changes to the magento CMS for example" you mean you are changing your cms blocks through the admin interface? or you are making changes to php/phtml files?
If you are doing changes on your cms blocks using the admin interface then you wont see your changes in git since those changes go to your DB, more precisely to cms_block table.
If you would like to migrate your content from your local to a testing/production server take a look to this tool: