How is QB64 written?

[Kernelpanic]

So, would it be helpful to learn C in order to better understand and/or contribute to QB64PE?

I can only advise you not to start with “C” now. Both together go wrong. Since you started with Basic, you should stick with it until the basics are learned. After that you can still try "C", but not both together as a beginner. 

See an example here:  https://qb64phoenix.com/forum/showthread...586&page=2