Followed UAVFutures' build guide on his MultiRotor Guide PDF found at Link.
Trying to stay under $200 as this will be my first quad and my budget is rather tight. Replaced the VTX with something else I found. I want to use this build log as documentation of the process I took and to keep notes so that I can prevent making the same mistake twice.

The Build
For being my first build, this wasn't too bad. I started by putting the frame together, ended up stripping a Torx bit and had to go get a proper tool from Harbor Freight. I had to use some pliers to grip the body spacers when screwing them in and ended up scratching some of them. After I mounted my motors and 4-in-1 ESC, I wasn't exactly sure which wires I needed to solder where. I soldered them in the order that made sense, but later on realized I needed to switch the right two wires on my front right and back left motors so they were turning in the right direction. Oscar Liang has a helpful image for this:

After the motors were soldered, I moved onto soldering the camera, VTX, and receiver. All were pretty easy after I figured out where and what I needed to solder. The Mamba came with a really helpful top plate that had the pinout for the FC. The camera only needed 3 connects, the VTX had 5, all were in the same area on the FC and the receiver needed 4. My VTX does not support smart audio so I snipped that wire for the camera rather long in case that's an upgrade I wanted in the future. After that was soldered up, I had to mount the VTX and receiver to the frame. I cut some foam from a box that my motors came in and placed some of it under my receiver, which I zip-tied to the bottom of my frame, and some under my VTX which I mounted to the top of my frame. This helped give some height to these components and gave something for them to dig into so they didn't move around as much compared to before when I zip-tied them without any foam. The battery connector leads that came with the mamba were too short, so I had to cut new ones.

A few days later, I finally received my goggles and was able to test the video signal. The signal was clear, I was seeing the OSD just fine, but there was no video. I re-soldered the camera and even tried connecting it directly the VTX input. No breakthrough. I spoke with some people on the UAVFutures' discord and we concluded it was the camera at fault. After the exchange, I connected the new camera up and it still didn't work. Spoke with more people on the same discord and it seemed I likely got two bad cameras.