I'm going to answer your questions first, then get into your critique. Firstly, in regards to your pens, it looks to me like you're drawing on a sketchbook that may be intended for graphite/charcoal/etc. and is somewhat toothier. As I explain here, this can really mess with how your pens perform. Sharpie ultrafines are themselves really cheap, and so combine the two and you're likely to run into problems (both in immediate performance, and with the paper soaking up a lot of ink and killing your pens quickly). I really do mean it when I said back in Lesson 0 that printer paper is best. It's smooth, works great with even cheap fineliners, and so on.

The ballpoint pen you ended up using is nice and all, but it has one key weakness - the line weight variation is minimal, especially on the lighter end. As you ease up on your pressure, where a proper fineliner will still make a mark, the ballpoint will get really faint and broken.

To your second question, in Lesson 0 I explain that your warmups consist of the exercises you've encountered thus far. Given that you're on lesson 2, then it'll consist of Lesson 1's exercises and the freely rotated boxes from the box challenge. Of that "pool" of exercises, you pick two or three at the beginning of a session and do them for 10-15 minutes. Some have some overlap, but ultimately it's not about "tell me which ones I should be doing". You should be doing all of them, on a rotation so you don't focus too much on any one. You're also not expected to do a complete page of each given exercise - just however much you can get done in the time you have.

Your other points don't seem to be questions - in the future, stick just to the questions. It's good to analyze your own work, but I specifically ignore self-critique so it doesn't interfere with what I end up mentioning in my own feedback.

So, starting with your arrows, you've done a good job of drawing them such that they flow smoothly through space. Do however keep an eye on the gaps between your zigzagging sections - they should be compressing at the same rate as the ribbon itself gets narrower, since perspective applies to all space consistently. You have some cases where those gaps are more inconsistent, and others where they can just stand to tighten up more rapidly.

For your organic forms with contour lines, you've done a good job of focusing on simple sausage forms. There are a few where the ends are of slightly different sizes, or where they get a bit thicker through their midsection but for the most part they're very well done. The contour lines themselves are also drawn confidently, with the ellipses maintaining an even shape, and the curves wrapping believably around the rounded forms. There's just one thing to keep an eye on - the degree of your contour lines tend to maintain a consistent width, which is not actually correct. The degree of a contour line basically represents the orientation of that cross-section in space, relative to the viewer, and as we slide along the sausage form, the cross section is either going to open up (allowing us to see more of it) or turn away from the viewer (allowing us to see less), as shown here.

Moving onto your texture analyses, you've largely done a good job of focusing precisely on what this exercise is all about - implying the presence of your textural forms through the use of clear, intentionally designed shadow shapes ,rather than outlining those forms. The only one I felt wasn't quite getting there was the bearded dragon scale texture, where you still did first rely on outlines, before adding shadows. When you got far into the right side, you focused on just drawing detached > shapes. Instead, as explained at the bottom of the diagram in this section, the part of the shadow shapes that would last the longest are those where multiple forms meet (resulting in `