Follow the instructions in this article to find a shared survey:

https://www.qualtrics.com/support/survey-platform/my-projects/sharing-a-project/#AccessingSharedSurveys

*Note the QTip under ACCEPT COLLABORATION BUTTON:

Qtip: You will need to have at least one project already in your account to see the Shared with Me folder and Accept Collaboration button. For help creating a project, read the Creating a Project page.

You will not see the Shared with Me folder until you create a survey first.  Follow these instructions for creating a survey:  https://www.qualtrics.com/support/survey-platform/my-projects/creating-a-project/