I think that's perfectly fine -- skip ahead if you like and return to the earlier chapters as needed. Worst case scenario, the amount of stuff you don't understand will be too much to constantly look up, so you'll have to make a smaller jump. Anyway when learning even more advanced math I think it's totally reasonable to forge your own path through a text (or multiple texts concurrently, if you like)

For sure, skip ahead :) Math textbooks are not generally meant to be read front-to-back (and math papers even less so). This one lends itself well to a straight-line readthrough, but what's important is what you get out of it.

As the sibling comment notes, if you skip too far ahead, the technical material will make you very well aware of that fact. But I think chapter 8 is a good place to jump in -- the material up to that point is mostly setting up intuitions and analogies. I think those are important to pick up, but they're also the kind of thing you pick up from sufficient exposure to mathematics of any flavor, so there's no harm.

Chapters 9 through 13 show how lots of other things can be seen as categories, so if you're already aware of some of them from undergrad math, you're probably good to go.