With the UPS Freight extension you must have a UPS Freight test account before you can get rates back. This is separate to your standard UPS account.
You can register for a test account on the UPS Freight site.
Once you have this you will need to enable "Test Mode" from within the extensions configuration panel to request access to production rates.
This will automatically setup scenario 1 in the UPS Test Guide for you which is below for your reference.
In order to display the total freight charge we recommend you switch off all handling/flat fees/etc and then just use the rate that is returned in the cart shipping quote for a business address.
Alternatively you can switch on logging and view the raw data. The request/response will be present if you switch on debug at the UPS Freight level. The entry you're looking for is "Price Arr" in the logs.
If this isn't working you can view the entire response UPS is sending by clicking on UPS LTL Response within the logger. To format the UPS Response take it and then paste into notepad, saving as response.xml. You can then open this file in a browser such as IE or Chrome and it will format it so it is more human readable. You can also search for TotalShipmentCharge etc in the response text if you prefer.
In order to get qualified for Production you then need to do the following:
We appreciate this is confusing for some but the constraints here are made by UPS, and not us.
Please follow our general installation instructions to setup the UPS Freight extension. Please be aware that you do need to integrate the files in app/design into your theme directories.