Black dots appear when rendering

I just downloaded Blender and made my first sketch of a something. As a newcomer, I had a few problems, but I got answers for all of them via google and youtube searching. All of them except this one. When the engine renders my model, black spots appear on it. I am frustrated and I will provide you a link to my thing. Please help me understand the problem and correct the rendering of my thingy. It’s seriously driving me nuts.

Attachments

untitled_2.5.blend (550 KB)

Go and actually look at your object in edit mode. Move some faces and you will then see all those overlapping faces. Delete them or remake the object