As we've told you before, in order to get a baby Pokémon from the egg the Old Man gives you, you need to walk around. The time it takes an egg to hatch depends on the Pokémon. The table below estimates how many steps you must give for that Pokémon to hatch.

Once the baby Pokémon pops out, it'll have the appearence of its mom, and, most of the time, some of the attacks of its dad. Newborn Pokémon are always level 5, no matter what. Remember that if the mother is an evolved Pokémon, for example, a Raticate, the baby will be its lowest stage of evolution, a Rattata.