[Find name of VM]

In a web browser, enter the IP address of your vCenter Server in the address bar, open vSphere Client, and enter your credentials to log in. Go to Hosts and Clusters, select the needed VM by name and check the Summary tab

[503 Service Unavailable error]

The HyperText Transfer Protocol (HTTP) 503 Service Unavailable server error response code indicates that the server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded.
 

[VM running Windows Server 2019 is very slow]

Might try standing up a new one for testing. Check latest cummulative updates have been applied. Check with server manufacturer for the latest firmware, chipset, driver support pack. Also try from a clean boot.

Hope this helps.

[Connect USB device to VMware]

Plug the external USB hard drive into the USB port of your physical machine.
Launch VMware Workstation.
Start your virtual machine.
Click VM > Removable device > external_hard_drive_name, then click Connect.