Hi Meer Alam,
Thank you for reaching out to us on Microsoft Q&A forum.
Step 1: Please refer the Unit 3 of https://learn.microsoft.com/en-us/training/modules/modern-analytics-interactive-experiences/3-exercise-use-power-bi-desktop-to-build-data-model. Kindly read the note section and click the below highlighted link.
Step 2: After selected the above highlighted link it's automatically downloaded the zip file.
Step 3: In lab 02B, we have a student guide also.
If you are still facing any issue, please let us know in the comments. We are glad to help you.
If the information is helpful, please Accept Answer so that it would be helpful to community members.
Thank you.