In order to use WSUS the PC needs to be in Active Directory. Once the PC is in Active directory you can run:

wuauclt.exe /detectnow

This will force the PC to talk to WSUS to get the updates needed instead of waiting for the PC to talk to WSUS.

To view the log go to c:\windows\WindowsUpdate.log or Windows Update.log
In the log you can view any updates the PC may need if any at all.

If you are having issues getting wsus updates try:

wuauclt.exe /resetauthorization /detectnow

This will force the PC to download a new certificate, and then download the updates from WSUS. Again check the log in c:\windows\WindowsUpdate.log to see if the Pc was able to reauthorize and obtain new updates.