I get that Canopy "is its own ecosystem" as my friend told me (when he explained to me that I didn't have Python on my computer and that's why my command line instructions weren't doing anything). Could this be the reason that it takes longer to load than Eclipse, which (I guess) I downloaded separately from Java? Or is it some other reason?
Good question! Fast loading was not a design goal of Canopy. Most Canopy users leave it open for many hours at a time, so load time (while always nice, of course!) was not as high a priority as having it include a robust scientific Python distribution. The technical reason why it loads slowly (especially when the OS's cache is "cold") is that it opens and interprets many tens of Python modules, some quite complex. Unlike C, Python is usually not compiled, so the startup time of Python programs is typically slower, though when important, there are ways to counteract that.