Good stuff man. Everyone starts somewhere and this is a really good start, take time and enjoy the learning process.
I started on my own and sorta beat my face against the wall until I got better at it. So I hope this helps you.

1. Break things down into shapes, it will help keep your work more consistent. You can draw the shapes lightly as a guide and erase them later if you wish, also look at the texture of things when you're out and about.
2. Play around with angling the pencil lead when drawing, different angles can give different shapes and effects. Some artists even just draw straights lines or circles to get better at drawing straight lines
3. This is purely a style thing but when drawing hair you can keep the hair flowing down or in a direction but making the lines all in the same direction. Tho you can keep doing your thing cos this style of hair as a neat grunge vibe.
4. When drawing things you want to looks scary or gross drawing the gums of teeth can really sell that vibe.