No worries! If you are new in programming or Python, do not worry. I suggest the following: Download or clone the entire respository:

https://github.com/ThomasAlbin/SpaceScienceTutorial

If you downloaded everything, let's take a look at the kernel_meta.txt in part 6. There you see some information header first (first 7 lines) and then the paths to the individual kernels (line 8 to 16). Take a look, e.g., at this entry:

../_kernels/spk/de432s.bsp

What does it say? The kernel de432s.bsp is in a folder called _kernels/spk (spk is a subfolder). As you can see _kernels is not in the part6 folder. You have to go back to the main directory where the other folders are visible (part1, part2, _kernels, etc.). To access the _kernels folder from part6 one needs the prefix "../". So, within the folder part6, we need to go back (../), to access _kernels.

You need to open the Jupyter notebook within part6 or change the working directory to part6. Unfortunately, the tutorial folder structure is a little bit ... unflexible. Sorry for that...