Welcome to NPN and the Macro forum, Jan. This is a nice set of images, but it’s a bit difficult to provide constructive criticisms without some information on what it was you were photographing, what you were trying to convey about it, and what kind of equipment and settings you used to photograph it. It’s also helpful for specific feedback if we know what software you’re using for processing your images.
The best way to get an idea of what you might want to include in your post is to read a bunch of other posts and the critiques of them. I’ve also found that one of the best ways to learn and improve it to provide critiques of other people’s images. It can be difficult when you’re first starting out but the Art of Image Critique article and the Critique Template are very helpful in that regard.
That said, I’ll try to make a start with your first image. There’s some really nice detail in this and I like the view of the sporangia (I think that’s the word). I do find it difficult to identify the intended subject in the image unless it’s the overall scene you were trying to capture. The little lichen that’s front and center looks like it could be the subject, but if so, I would have expected you to get in closer or crop more tightly to help emphasize it. I also find the out of focus plant in the lower right corner pulls my eye as does the very bright out of focus twig or needle in the upper right. I think if you cropped in from the right far enough to eliminate those two distractions and from the bottom far enough to eliminate the dark, rather featureless area down there, you’d have a more coherent composition.
Again, welcome to the group. I think you’ll enjoy the journey here and don’t hesitate to ask questions if we say something you don’t understand. I remember how baffled I was by some of the terminology when I first joined.