The SAP site for Focused Run has a link to the online Focused Run demo system and link to videos.
First visit the general SAP Focused Run site. Now scroll down to the resources part:
On the right hand side are the video.
In the middle the Demo System link. You can also access it directly via this URL.
Scroll down to the landscape overview. To access the system press the blue “SAP Focused Run launchpad button”.
The user ID and password is in the table below the button.
Older background material
Some older, but still useful, background material can be found on this link.
Another potential avenue for demoing Focused Run is the SAP Cloud Appliance Library which has Focused Run images available to deploy on AWS/Azure/GCP. It is not free as you do incur cloud costs but if you needed to spin up a FRUN install quickly it might be a good option. Especially because the demo restricts access to somethings (template maintenance, SSI, etc).
cal.sap.com
Specifically for SAP focused run:
https://cal.sap.com/catalog#/applianceTemplates/f4a6643f-2731-486c-af82-0508396650b7