Connecting modules (SASS, Gulp, etc.) - do I need to upload to the project folder every time?

Question

npm

Um, guys, just don't laugh. In short, such a thing, every time I download the SASS, Galp and other things modules into the folder with new projects. It seems to me that this is not ok. Question: how can this process of connecting modules be automated?
PS I'm generally a humanitarian, a beginner, I understand little (I've been working on the web for 3 months)