To get the list of all the commands installed in the system use the below command line. It will include all the Alias, Functions and Cmdlets.
Get-Command
To export them into the CSV file,
Get-Command | Export-Csv D:\Temp\PowerShellcommands.csv - NoTypeInformation
To get only the cmdlets commands,
Get-Command -CommandType Cmdlet
Similarly, you can get the commands for the alias and functions.
If you want the list of commands starting with getting, you parameter –Verb.
Get-Command -Verb Get
To get command starting with Set,
Get-Command -Verb Set