As a design decision that level of information isn't there in the core rules. The combat round is pitched at a level of detail above where most RPGs are, which gives players and storyguides the opportunity to be a litle more free with the set piece action encounters. But the trade off is, of course, that it can confuse people coming into this edition, or the game as a whole. And it means that lots of people have to come up with their own movement rules.
I'm pretty sure that there's a thread on here somewhere that gives at least one way to crack it.
It'll be something like:
Walk: 6 + Quickness paces
Run: 12 + Quickness + Athletics paces
Sprint: 18 + Quickness + Athletics paces
If you can't find the thread in a search (I couldn't) then just play with the above until you're happy you have some reasonable distances for people to travel over a 6-second combat round.
I'd keep your ear to the ground for any future releases that may provide additional input into this.
And welcome to the game!