I've studied with (now) engineers and there is large portion of people having a hard time with even the concept of a function. We learned C(++) at the time. I guess being forced to learn about what the hardware does kinda messed with people being able to just think about algorithms. As a first programmig language to just write some basic functions I like Python, but to be honest I don't understand what's going really going on behind the scenes either. But C is a really solid choice, as what's really happening is easy to reason about (at least unoptimized) and every other language will have to abstract these same concepts.