To create a project click the green button New project on the right upper corner of the dashboard and a new window appears. Then give a project a name and decide if the project is going to be Private or Public.
The private project can be seen only by invited users and the public project can be seen by everyone from the team, but only the invited users can edit it.
To invite people to the project, click the avatar icon and then the Manage users link. A window for managing users appears, where you can add as many users as you want and assign them different roles.
For easier understanding watch the GIF below.