A great way to track tasks that need to be worked on in a GitHub repository is to use GitHub Issues. GitHub Issues are built into GitHub and list the title, description, and assignee for an Issue. Other features are included as well, such as designating milestones and creating labels to keep everything in a repository organized.
A GitHub project can be useful for creating and tracking issues, pull requests, and notes which can be created as cards. These cards can be placed in columns of your choosing.