I wish you the best of luck. When I started down this path I ended up grabbing code from several commerce products written in PHP to see how they did it as I could not get the UPS examples to work. Turns out most of them are just doing a POST and manually assembling the XML instead of using SOAP, since it's so painful.
But, regardless, what it wants in $wsdl is the wsdl file location.
End point url is the UPS url for the service you wish to use, for example, for TimeInTransit:
For prod: https://wwwcie.ups.com/ups.app/xml/TimeInTransit
For test: https://onlinetools.ups.com/ups.app/xml/TimeInTransit
EDIT: It appears that the urls above are incorrect. Reference: https://developerkitcommunity.ups.com/index.php/Special:AWCforum/st/id267
Once your testing is completed please direct your Shipping Package XML to the Production URL: https://onlinetools.ups.com/webservices/Ship
They should read:
For test: https://wwwcie.ups.com/ups.app/xml/TimeInTransit
For prod: https://onlinetools.ups.com/ups.app/xml/TimeInTransit