To add a response to a Web Form, click the "Add Response" link in the Web Form listing. This will take you to the first page of the form. Note that based on what the singular value of the form data is in the Form Settings, the link may be different (for example, "Add Employee" instead of "Add Response").

Note: Not all Web Forms will be enabled to allow public users to fill them out. Some may only be enabled to allow users to view the responses that have been submitted by form managers. If you do not see the "Fill Out" link in the Web Form listing for the form you wish to fill out, it is not enabled for public submissions.