Can't save files onto actual desktop

I am very new to Mac and have a rather stupid question. I was playing with my new macbook and realized I couldn't seem to place files onto my desktop. The files are there, as I see it in my "desktop" section in my Finder. But as I try to drag that file onto the actual desktop (for later easier access), it won't let me. As I've been searching online for some guides, I also notice from pictures that my "macintosh hard drive" icon is not on my actual desktop. Is there a setting I by accidently switched off? Thanks so much