Even if you use seeds from ripe fruit from a tree with good production, you still don't know. If it doesn't flower at all when it has been in the ground for six months, it's a male. If the flower is fairly round with five separate petals fused around a tiny fruit at the base, it's a female. If the flower is tubular with both a small fruit, or ovary, and a stamen, a slender stalk encircling the ovary, it is an hermaphrodite. Papaya seeds or seedlings should be planted in well-drained soil, high in organic matter because they grow quickly and need a steady supply of nutrients and moisture to thrive.
Sunny areas protected from the wind are best.
The root system of a papaya tree is delicate, and is apt to rot with over-watering. The seeds will germinate in about two weeks. Planting holes should be spaced 6 to 10 feet apart. After 6 to 8 weeks, the plants should be thinned, retaining only two or three of the strongest in each hole. Then wait until they flower.