Congratulations! You have just created a nice map. Of course, it has some more or less obvious flaws, but I would have been very pleased if I could manage to create such a map back in my school days. Some of the flaws are more obvious, like polygons sticking out from the administrative boundary. Well of course, we can consider it artistic, but a proper map either clips its content to an irregular shape, or continues to show its thematic beyond it. We will fix that in the next chapter. Less obvious flaws are the occasional dangling lines disconnected from the visualized river and road networks, or the ill-placed labels, which would be quite hard to correct from QGIS. However, don't worry about these for now; just enjoy the feeling that you have just created a great map.
If you followed the entire chapter in one sitting, take a rest. That was a lot of knowledge compressed...