Four seeds
The standard game: four seeds in each of the twelve pits, forty-eight in all.
This is the default and what nearly everyone means by Kalah. Four seeds in each pit, twenty-five to win, twenty-four each a draw.
Four is exactly the distance from A3 to your store, so the game opens with a free move on the table and a scrap over the ones after it. Handfuls stay small enough that most moves finish inside one lap, which makes traps easy to plan two or three turns ahead.
This is also the board computers have solved, so rated games lean on the pie rule. Learn here first; almost everything you work out about traps and free moves carries over to the others.