You've just download LabVIEW or the driver for the instrument? If it's the driver, then the first step is to connect the instrument to the GPIB board in your pc and then open MAX (Measurement & Automation Explorer). Go to Devices and Interfaces, expand that, and right click on your GPIB board that is listed and do a scan for instruments. If it doesn't find anything, then you've got problems. If it does find the instrument, make note of the GPIB address.
Assuming that the instrument was found, open Example1.vi in the driver. The driver was not written by NI and there are some problems with it. The first problem with Example 1 is that the address of the instrument is hard coded on the diagram. The diagram uses address 7. If that's the actual address of your instrument, go ahead and run the VI. If it's not, change the address on the diagram and then run it. The VIs in the driver have a lot of other problems. Mainly, they don't do any real error checking but if the example VI sets voltage and current, then you're probably okay. There's also no help for any of the VIs, so you'll have to study the diagrams of the different functions, see which instrument commands they implement, and go from there. You'll need the instrument programming manual as a reference.