Making a Pixhawk Quad Fly Sideways!

Hey all! I am a student currently working on replicating the Hippocampus UUV ( as a hobby. I have experimented with the airframe/mixer system to a fair degree of success. Issue I am currently having is that while I can pilot the craft manually to some degree of success I am unable to use the point to point autopilot feature(qgroundcontrol).

Due to the fact that I am referencing the rc.mc_defaults when I attempt to have the vehicle “takeoff” it still wants to ascend like a normal quad would. I am still attempting to understand the firmware so any help that could be provided would be greatly appreciated.

Pixhawk Cube
4-in-1 ESC

Goal: Have the UUV be able to navigate on the horizontal plane (3D space not necessary at the moment) using point to point navigation while maintaining active stability.