To breed on Pokemon Sapphire, you need to put 2 opposite gender Pokemon in the day-care. They have to be in the same egg group, or look alike. You can check the likeliness of them having an egg by talking to the day-care man outside the day-care. If he says they like each other, then you're gonna have an egg.
All Pokemon in Pokemon sapphire can breed. Except for all legendaries.
ditto
You can't
U cant breed Rayquaza because its a legendary Pokemon but u can breed other Pokemon as long its not legendary.
In Pokemon Sapphire, the only egg you get from an NPC is the Wynaut Egg from the old lady in Lavaridge Town. You can get an egg from any Pokemon that can breed, as with any other Pokemon game that has the Day Care that allows you to leave two Pokemon there. You can breed any Pokemon that can breed with Ditto (except for another Ditto), which can be caught in Pokemon FireRed and LeafGreen and traded to Sapphire.
either a Female pichu or a ditto
Have a Ditto and breed with whatever Pokemon you please at the daycare. You can't breed Legendaries. If you don't have a ditto, search which compatible Pokemon is best to breed with the Pokemon you want.
breed deoxys
breed pikachu/raichu
Another Abra of a different Gender or a Ditto.
Trade, Train, Evolve, Breed.
A ditto, if you can get your hands on one.