You cannot change UI objects without directly inte3racting with that UI object, via an API, or the default object Model. CSOM is what SP uses for the latter. Just do a search for ‘powershell csom sharepoint’ to get resources to review about dealing with that.
Example hits:
CSOM SharePoint PowerShell Reference and Example Codes
https://social.technet.microsoft.com/wiki/contents/articles/29518.csom-sharepoint-powershell-reference-and-example-codes.aspx
See also:
SharePoint: A Complete Guide to Getting and Setting Fields using PowerShell
https://social.technet.microsoft.com/wiki/contents/articles/20831.sharepoint-a-complete-guide-to-getting-and-setting-fields-using-powershell.aspx
You say you are new to PS, the it is vital you get ramped up on it first, to decrease the confusion, misconceptions, errors, bad habits, bad code and the like…
PowerShell Standard Library: Build single module that works across Windows PowerShell and PowerShell Core
Windows PowerShell Best Practices
PowerShellPracticeAndStyle
PowerShell scripting best practices
Powershell - Recommended coding style
What is the recommended coding style for PowerShell?
PowerShell 4.0 Best Practices scripts
This is a place holder for all the scripts from my forthcoming Windows PowerShell 4.0 Best Practices book. Once the book releases, I will upload the 200 scripts to this location – which is currently referenced in my book. The idea is similiar to the one that I did for the Wi