no sound

Hello, i purchased the DDJ-FLX4, but i'm having a hard time getting any sound. I verified on both Win11 PC and my MacBook Pro M4. It was working from my Mac speakers yesterday, but today nothing. No sound from my PC at all. I thought it was because i didn't have studio speakers connected via RCA port, so went and bought speakers and cables today, but I'm getting echo from the speakers. Headphone jack doesn't provide any sound at all; I've tried 4 headphones and still nothing. I have no idea what I'm doing wrong. I even downloaded the VAC software thinking that would fix the issue, I was wrong. I followed the instructions to setup the mixer, but i must be doing something wrong. At this point, I'm ready to bring everything to actual DJ to help me set this up. I have to find a DJ now. Any help? I may have gotten a lemon. Not sure.