The command-line workstation (CLW) is a jarfile in the lib folder of the Enterprise Manager (EM) installation.
If you have an agent installed, it must be reporting data to the Enterprise Manager, so I would assume that the Enterprise Manager has already been installed.
This is the documentation on CLW
https://docops.ca.com/ca-apm/10-5/en/using/apm-command-line-workstation
We do not know your installation path, but you can search for CLWorkstation.jar on the machine where Enterprise Manager is installed and there should only be one of them.
You can copy that jar file from the Enterprise Manager to another machine where it might be more convenient to run for you.
Try to be as specific with any regular expressions you use for querying data as large queries can have large negative consequences on the Enterprise Manager.
Trying not to confuse things, Introscope Workstation is a GUI that provides access to view metrics,dashboards (that you can configure), documentation on this here
https://docops.ca.com/ca-apm/10-5/en/using/apm-workstation#APMWorkstation-TheWorkstation,JavaWebStart,andWebView
The Workstation does not necessarily need to be installed, you can access the Java Web Start version. You can go to port 8081 (by default) of the Enterprise Manager with a browser, and click the link to "Start Introscope Workstation"