Alpha Kingpaca is a level-23 boss around (50, -460), northwest of Small Settlement. The settlement's fast-travel point is around (73, -485). Head northwest from there, adjusting your route around the terrain.
Leave yourself room to retreat
Use Small Settlement as your return point, then approach the boss area on foot or with your preferred mount. The encounter coordinate points to Kingpaca, not a shop or travel statue.
Pause at the edge of the fight and pick an open direction to move when Kingpaca attacks. Check that your escape route will not take you straight into another group of Pals.
The nearby settlement makes the trip convenient, but Kingpaca is still level 23. If your party is much weaker, mark the location and return after upgrading rather than using up your supplies on a fight you cannot control.
Watch for Kingly Slam
Kingpaca is Neutral and has Kingly Slam, a jumping body attack learned at level 22. You can attempt this fight during the day or at night.
When it leaves the ground, watch the boss and keep your dodge available. Trying to finish a stationary attack or squeeze in a sphere throw can leave you with nowhere to move. Resume attacking once you have space to see the next action.
Keep an eye on your accompanying Pal's health as well. Swap it before it collapses if the fight is going badly. If it is comfortably dealing damage, concentrate on positioning and preparing the capture instead of adding every attack you can.
For a catch, stop the heavy damage while Kingpaca still has enough health to survive another mistake. Switch to a weaker weapon or recall your Pal before the final throws, then use the displayed capture chance to judge your spheres.
Decide how Kingpaca fits your party
Kingpaca's riding technology unlocks at level 23. Its current partner skill gives it Defense and movement-speed benefits from Melpaca in the party. Check this role before following an older build that assumes a different partner effect.
If you want a mount, craft its equipment and try a familiar route first. If you want to build around Melpaca, weigh those party slots against the companions you use for combat and gathering.
For reward farming, the Alpha's table lists Metal Armor Schematic 4 at 3%. Plan for repeat runs rather than expecting the schematic with your first catch.
Return to the Pal location finder, or read about Alpha Mammorest before approaching that larger boss near the starting region.