Hello. I'm trying to start on the Build A Data Model for a Recruiting App Project. https://trailhead.salesforce.com/projects/build-a-data-model-for-a-recruiting-app/steps/create-a-custom-object-for-reviews It asks that I install an unmanaged package but when i click on the link provided it says the app cannot be installed because the package is not found. 
"The requested package doesn't yet exist or has been deleted. If this is a recently created package version, please try again in a few minutes or contact the package publisher."
I need to understand roll-up fields (starting from the basics) so i need to complete this or is there another, newer module that will explain it better?

Can you pls help on this question.
Q) What can an administrator configure for users on the search result page? Choose 3 answers
a. Columns displayed for each object
b. Filter by which users can narrow down results
c. Number of records displayed for each object
d. Fields being searched on for each object
e. Objects included in the search a. Columns displayed for each object