Select Projects > Projects from the top menu, then click Add Project.
In the Name field, type a descriptive name for your project (typically two or three words, e.g. Purchase Orders).
In the Key field, type a meaningful prefix for issues in your project (typically three or four characters, e.g. ORD). Be aware that you cannot subsequently change this in JIRA.
In the Project Lead field, select the user to whom issues should be assigned by default.
If you chose to set up email when you installed JIRA (see above), change the Notification Scheme field from None to Default Notification Scheme. This will allow JIRA to automatically send emails to appropriate people when particular events occur (e.g. 'Issue Created', 'Issue Resolved'). For more about email, please see the documentation.
Leave the rest of the fields with their default values for now. Click the Add button.