How can I learn about every facet of my computer?

There are so many files, programs, etc. on here that I an unfamiliar with that I am perpetually frustrated. Will one computer cl clarify things? Is there another way? Each time I download something I feel like I am receiving a whole bunch of sinister "something's" to boot. Spyware or malware. And now, my pc is malfunctioning. And creating things without my knowledge or istance (like music folders, out of the blue.) Thanks in advance.