Like Gary already said, you seem to be adding a lot of pressure on the pencil. It can make the lines a bit wobbly, and hard to erase in case you need to fix something. Try drawing in short, light strokes, and maybe use the grid on the paper to help you do straight lines.
You should also practice doing smooth curves with longer strokes, which can be especially helpful when drawing long hair (fror example).
Also, how do you hold your pencil? Since you seem to be adding a lot of pressure, I get a feeling that you hold the pencil in over 45 degree angle. Of course I can’t be sure, but if that’s the case, try going for a lower angle with the tip. It helps relieve the pressure from the tip, and makes smooth drawing easier.
Here’s also a tutorial I picked from YouTube, to help with the hand eye coordination and pen pressure. I decided to link it, since embed videos can really slow the page down. There are other tutorials on the related videos, so maybe move on to those when you feel like you’re good to go.
Oh, and if you’re going to smudge, you don’t necessarily need to use a finger to do it (although it’s good method, and I use a finger to smudge too). BUT, you can also use household, or toilet paper to do the exact same thing, but without dirtying your fingers too much (or breaking the skin in the worst case). Just fold the paper to a small pillow, so it’s easier to see what exactly what you are smudging.
Also, some graphite will be left on the paper, and it can be used to lightly darked larger areas very easily. But you will often have to restrengthen some lines after paper blurring, since it can be a bit imprecise method (although quicker and easier).