Hi there! Welcome to the Community!
Git doesn’t automatically see the changes - it only sees your commits. A commit is like you taking a snapshot of your folder at that specific point in time. So, to improve your contribution graph, you’ll need to remember to make frequent commits and push them up to GitHub.
You also need to double check that the email address in your Git settings is correctly set up to be an email address connected to your GitHub account.
If it’s mostly the cosmetic appearance of your contribution graph that you’re interested in, you might be interested to know that it is possible to manipulate all the metadata of your commits to make the contribution graph look however you want. Some people get really creative with it!