Cubase 9.5 Pro with Mg16Xu Board (Recording issues!)

Hello My name is Trey I just recently purchased the Cubase 9.5. I’m having issues recording my live guitar and seeing the wavelengths to justify its being recorded. In other words, I monitor the channel and hit record and I get a flat line wavelength. I attempted to zoom in as well and that did no good as it was just a flat line still. The Audio inputs/outputs are exactly the same (The mixing board)—‘maybe that’s the issue’ but when I go into studio setup it shows that I am using Yamaha Steinberg ASIO. I can’t hear the playback either when I attempt to record, I have tried every channel but I get nothing. It doesn’t make sense to me, I feel like the issue could be extremely easy to solve I just lack the intuitiveness to solve it. My mixing board is the Mg16Xu and I may need tips on how to arm my mixer for cubase to receive it. I’m clueless…