When testing, there are multiple ways you can see what an applicant sees:

• Simply click Preview from Manage view to get a basic overview (however, this won't show the Notes to Applicant)
• Use the Submit by Proxy button from the Manage view to actually practice submitting an app. This will bring up the form that you use to apply by proxy. Type in an email address to begin filling out the form as an applicant would. To submit a test application, use your own email address or that of a colleague. This will show what the form looks like, and any notes you've added will appear as tool tips when you start to fill in questions.
• Use a different user account (created using a different email address) to log in and apply. This will show you the exact experience an applicant will get. 

If you want a more detailed experience, or if the opportunity is already in progress for "real" applicants, follow these steps:

• First, create a copy of the current draft/opportunity by viewing it from the Manage tab > Copy button. This way, you can do any testing on this copy without affecting your "real" process. Just make sure to re-name the copy something obvious to distinguish it.
• On the Details page, make the Remove from Homepage Date in the past (so it won't show and people won't accidentally apply to it).
• Go to Finalize, launch. At this point you can then:
  • Have colleagues test by sending them the direct link to the test opportunity (You can send the link from the Share button).
  • Or test yourself by creating an Applicant account for yourself in the system. In that case, you would want to have a direct link in order to access, which you can also get from from the Manage view> Share button.
• You can then return to your original opportunity and make any necessary edits.

If you want to test what a reviewer will see, read this article.