Your scanner works like a keyboard or a mouse: you should just be able to plug it in and have it work, just like a keyboard or mouse. If your new scanner is not working properly, the first thing to check is the USB port into which it is plugged. Try it in a different USB port, and if the problem persists, look below for another option.
Sometimes with Motorola (now Symbol) handheld barcode scanners the item will not initially work properly. If you scan a barcode and nothing is happening and you have a model similar to the one pictured below, here is one thing you can try to troubleshoot the issue.
Click below to download the PDF file. This file is a page from the manual for this series of barcode scanner. On the page you will see a single barcode. Print the page out at Letter size on a full-size printer and then scan the barcode on the page.
This will 're-code' your scanner to properly scan your barcodes.
If the problem persists, it is likely an issue with the barcode scanner unit itself, and you can try Motorola / Symbol's technical support at (888) 325-9336.