One of the first things you will want to do is set up your default commission rate. The default commission rate is the rate given to affiliates when they register with you, and it will determine the percentage the affiliate will earn when they convert a referred order.
To update the default commission rate, visit your shop settings page. Access the settings page by clicking on the cog icon in the navigation menu on the left or using the drop down menu by clicking on your name in the top right corner. (You may also click here.)
From the setting page, look for the "Info" block. Set your desired default commission rate and hit "Save" to commit your changes.