How I can preview the ticket form my customers need to fill in before they contact us?
By accessing the ticket form settings
A ticket form is a set of predefined ticket fields for a specific support request. To see your ticket form, click the Admin icon () in the sidebar, then select Ticket forms. Only ticket fields that are editable for end users are displayed in the request form. To change the order each field appears in the form, drag and drop them in the desired order.
By assuming end-users identity
An administrator can take on the credentials of an end user to view and use Zendesk Support as that end user. This allows you to visualize what your customers see when they create a ticket using your request form. For instructions on how to do this, see the article: Assuming end-users.
By previewing your Help Center
The Help Center offers you a feature that allows you to preview changes while you're working on your theme. For more information, see the article: Previewing your Help Center theme.