Hi Crystal Swanson,
Thank you for reaching out to us on the Microsoft Q&A forum.
Adding tables of data to your Power Apps app is a straightforward process. For learning purposes, SharePoint Online lists are an excellent data source, especially since they are included in most Office 365 subscriptions at no additional cost.
In this module, the SharePoint Pets file is part of a knowledge-building exercise designed to help you work with external data in a Power Apps canvas app. To complete the exercise successfully, you can find the download link within the module, as illustrated in the exercise screenshot.
Please follow this link to access the exercise: Work with external data in a Power Apps canvas app.
Once you download and extract the spreadsheet, you’ll need to upload it to your OneDrive and follow the steps outlined in the exercise to connect it as a data source in Power Apps.
If you are still facing any issue, please let us know in the comments and where you are encountering this error along with the screenshot for reference. We are glad to help you.
If the information is helpful, please Accept Answer and Upvote so that it would be helpful to community members.
Thank you.