Hi,
here's how to achieve this :)
First, go to Clearpass Guest and then to Configuration -> Pages -> Fields
As you can see, there is a field named auto_send_smtp. This field will automatically send an email to the provided e-mail adress.
For the Password auto generation part you will find a field named : random_password
When you click those fields you can edit them and personalize them a lot to your needs. The description of the fields are quite self explanatory.
Next you need to add those fields to your Guest Creation Form.
Go to Configuration -> Pages -> Forms and Views and then select the create_user form (if this is the one you are using) and click "Edit Fields".
Now add the fields, you should end up with something like this :
You can customize the auto_send_smtp field to make it Hidden or to see it. In this example I selected checkbox and saved with default values.
Next you should launch the page and have something like this somewhere in it :)