# This downloads and installs the posh-git and oh-my-posh modules from PowerShell Gallery.
# The former shows Git info in the prompt, and the latter provides the themes.
Install-Module posh-git -Scope CurrentUser
Install-Module oh-my-posh -Scope CurrentUser


# Next, edit the PowerShell profile loaded at startup. In PowerShell, $PROFILE shows the current
# user's profile path. The file may not exist; run the commands below to create it and open it.
if (!(Test-Path -Path $PROFILE )) { New-Item -Type File -Path $PROFILE -Force }
notepad $PROFILE

Add the following commands to the profile file:

Import-Module posh-git
Import-Module oh-my-posh
Set-Theme Paradox

oh-my-posh includes many themes. You can use the Get-Theme cmdlet to list all available themes and their file locations.