What software and do you have? Do you have the USB cable to go from the computer to the scanner? If so load the drivers for the cable and see if you can read the scanner with it.
For example if you have the WIN500 software... you are already a RR premium member so run the software... go to file... web import... radio reference. Log in to RR... then navigate to your state and then county. There are 2 choices... trunked and conventional. If you give us a little more info... we can help you better.
Really you should sit down with your manual, but if you have lost it, the Easier to Read manual is a start. Next you should sit down and look at your software (I'm going to guess you got ARC500, but feel free to correct this). Both ARC500 and Win500 have user guides which are linked in the software article. You will also need a USB cable - and we have an article on this, too...
You haven't entered a location (county/state is fine) which makes it next to impossible for folks from your area to help you. As the article mentions, we have many state forums - certainly someone local to you is a good place to start to get help