Blender Begginer HELP

Hello I"m brand new to Blender, and I could use some help. I started the Fancy Watch Tutorial .
I have run into a few problems. The 1st is black “smudges” when i render the object, these are quite apparent. The 2nd is when following instructions to mirror a piece of the band it doesn’t appear where it should.

Problem 1

Problem 2, and SC of tutorial step


Any positive input or advice would be helpful Thank you

The black spots are from doubled faces. It happens from two faces being right on top of each other. Maybe left-over from a step that you did over?
The object appearing in the “wrong place” is easily fixed… just move it to where you want it to be (G key).

Using GY key combination, you can just slide that piece into position.