No it’s not just you. These challenges are doable though and the projects will help you to connect with the material. I must add that I have several years of experience with js. If I were new to this, I would have experienced them very differently. There must still be some despairing posts of me floating around on the forum somewhere. God, it was awful, those first node and express projects (done with the previous curriculum). Never have I felt such misery and despair.
I also believe one is supposed to use these challenges as a starting point. Looking up material is part of a developer’s job.
The next section is worse still. You will basically be copying weird code into more weird code and this time there won’t be much explanation. Just grit your teeth, and get it done. Again, the projects help you to connect with the material and there are free mongodb courses available. I believe a certain stubborness is part of any programmer’s psychological make-up. And the capacity to communicate and ask for help of course.