KINGMAKER is an epic campaign for Pathfinder 2E. Your adventure begins in Rostland, located in southern Brevoy, but moves fairly quickly to the southwest into the infamous Stolen Lands, the northeastern most reaches of the River Kingdoms. Here, a vast swath of wilderness awaits exploration and settlement. The nearby kingdom of Pitax lies along the southwestern border of the Stolen Lands, but whether they will become your friends or enemies, only time will tell.
Here you will find some useful resources throughout your adventures in Kingmaker:
Archives of Nethys - Official system reference document (SRD) of the Pathfinder 2E rules.
Pathbuilder 2E - The premier character builder, planner, and sheet for Pathfinder 2E. It automates everything and is incredibly useful. Worth it to pay the one-time fee to get the premium bonuses.
PF2.tools - A repository for all the online tools you need to play and run a Pathfinder 2E game.
Paizo.com - Site of the company behind Pathfinder (and Starfinder). Go here to buy books, check out official forums, or participate in Organized Play.
Kingmaker Player's Guide - Spoiler-free advice and specific suggestions to help you create a character tailored specifically for Kingmaker. As always, do not be afraid to ask your GM if you have any specific questions. There will be a group Session Zero and one-on-one sessions to help finalize everyone's characters before the campaign starts.