Many years ago when I was learning BASIC as a kid, I heard about using pseudo code as a way to prototype the actual code that you were trying to write.
I also remember hearing the suggestion of writing functions first.
However I wanted ask if there are any modern resources to learn how to plan code writing.
Yes, start by reading Casey's method of "Semantic Compression" which is, start the usage code first and then see what needs to be pulled out into functions/files etc.