DJM 450 - Nothing happens when I connect usb

Hi everyone

I'm hoping someone can help, firstly I'm really new to this technology. I'm an old vinyl dj person and never really used software before. I have two reloop 7000mk1 and the DJM 450 with Rekorbox and DVS built in (apparently). I'm getting audio from my decks without any issue but when I plug in the usb from the mixer to laptop nothing happens. I have no idea if the software is registered, it asked me to pick a plan, I've checked, everything seems up to date with software, drivers ect. I'm at a complete loss. I thought I'd just plug it in and go..... 

I'm really hoping for an easy to understand guide on what I'm doing wrong or what I need to do. 

Thanks in advance