Unable to insyall salesforce adoption dashboard to tackle the challenge as in   https://trailhead.salesforce.com/modules/reports_dashboards/units/reports_dashboards_appexchange .

I get the following error on clicking the link to install  

Oops! Looks like you don't have permission to install apps.
To keep your Salesforce secure, only system administrators have permission to install apps or components. Please contact your Salesforce system administrator to install this app or component.
Or if you're feeling adventurous, sign up for a new free trial of Salesforce so you can install and try out the app or component on your own. 

Need help to install this so that I can complete  Reports and Dashboards module

On clicking Run All  getting this error. Please help.
Failed to enqueue tests.: An unknown exception occurred

Having a challenging day with all of my Trailhead exercises today, All 3 have not gone well, I guess this is a learning experience

Ok, here is the error I'm receiving for his challenge. 
Challenge not yet complete... here's what's wrong: 
A Visualforce page named 'FlowPage' was not found.

I will add the screenshots below:
1. New Customer Flow

2. FlowScreen
2. 

3. Account Creation

3. Contact Creation

4. 
Opportunity Creation

4. 

I will add the screenshots for the Visual Force Pages on part II of this