The Path of Skulls, like all stories in The Thirteenth Doctor #0 (also known as the Many Lives of Doctor Who) is very short. Keeping in mind these are shorts within a single issue of a comic book, these things are only going to be a few pages long and not have a ton of substance to them. Path of Skulls is very much that - full of lavish artwork of both the TARDIS and an alien planet, we get a lot of good visuals but very little in the way of plot. The Doctor and the TARDIS crew come across a number of skulls on a trail, and quickly deduce it is not something malignant but rather a respectful spiritual site of some kind.

I like that this suggests not every adventure in the TARDIS is some big, sweeping epic story, but rather sometimes the crew really are just travelling, but that's all one can really take from something this simple.