Hi Eli,
Welcome to the community forum!
As far as I understand, you have built Visual Studio Code from the open sources. If it’s so, then VS Code requires a GUI to operate. Navio2’s Raspbian image doesn’t have the GUI by default.
Although it’s possible to install packages to run GUI, it’s not truly reasonable to run it on autopilot. Also, it’s not recommended to install the GUI for an operating drone.
I’d suggest using the default text editor nano or installing vim.