Hello, if you are using paint.net and trying to re-size your image to become bigger to be actually seen. Then you maybe have run into this problem. The image becomes blurrier the more you re-size into a bigger size. To fix this, when you select the thing you want to. Aka this Now when you press "Move Selected Pixels" Above it, it should say "Quality: Smooth" Change that to "Quality: Pixelated" There. Problem fixed. Now, I shall show you what happens when you try to re-size the image with it Smooth. See, It looses some of the color and the lines. But Paint.net was just being grateful. Sometimes its much worse.
Or you could go to Image>Resize... The way you did it isn't very exact, it might mess with the shapes of the pixels.
Make sure you save the file as a .PNG too. I personally use mspaint for resizing since it takes literally like 5 seconds.
Mspaint is already the default art program, right there and ready. Select resize, then choose size. You have an option of by percentage or pixel, also allows skewing option if so wanted. It's my number one resizing program for pixel work.
Pretty simple in Gimp too for those who use it. In the toolbar, Image > Scale Image, Change interpolation to None.
I think this guide is fine, screenshots, clear and simple steps easy for beginners fresh in the art/digital art scene. Keep it up