first 30 min class

Good start. Yes, you should start keeping track of your work (date it so you can come back at a little time & see what progress you have made). Line-of-Action has a section on Faces & Expressions. Check it out. Also, do a study of human anatomy - muscles & bone structure. You are on the correct path. Also, remember the head has a skull that is rounded (not a problem here with your heads). In a local portrait session, some of the people drew the face OK but the back of the head was flat. Not correct. Also, important to remember: Practice makes better. So, get busy practicing.

I think you did a really good job of making each face distinct. But one of the things you need to work on is the lines. There are very many and can confuse the eye. It also makes it look a little sloppy. A way to improve is to look at a reference photo and challenge yourself to use the least amount of lines possible. Great work!

One world. Control! You have understood the basics of head anatomy but lines are too sektchy. practice more on basice shapes and putting them into prespective rather than rendering.

I would practice with the facial expressions on this site and also look into Loomis etc. in terms of how to break the head down into simple shapes. You will learn more if you focus on where things should be rather than where they appear in a reference etc.

If you're just learning I would advise learning the anatomically correct way of doing things rather than animation style (which I think is better for gesture study).

There is nothing wrong with sketchy style art, but push yourself to using less and less lines. Less lines = more confidence.

The two on the left look pretty good, the one on the right has some big perspective issues so I would probably look into that.

For a first class these are great just buckle up and start grinding these out daily and you'll see improvement.