To add a project, proceed from "Add Project" on the list of "Projects" page.
Enter "Project Name" and "Project Key" and press "Submit" to add a project.
Project key is an abbreviated name (code name) of the project. It is used for the name of issues (i.e. BLG-52).
By checking "Use Chart" box, you can use Gantt Chart and Burndown Chart.
You'll be able to input Start Date and Estimated Hours/Actual Hours of issue.
Checking "Enable Subtasking" box will let you use parent-child issue relationships for this project.
"Formatting rules" is to set the formatting rules for this project. "Backlog", "Markdown" or "Use Space setting" options are available.
Formatting rules for the Space can be set on the Space settings page.