One of my friends told me that if I breed two Ditto I might get a random Pokemon. But none of my Ditto like each other. So I'm wondering if I am even able to breed two Ditto with each other to get a random Pokemon.
Ditto is a very special Pokémon. It can breed with most Pokémon, regardless of gender (or lack thereof), and the egg produced will always belong to its partner. Ditto is also the only Pokémon that can breed with a legendary Pokémon or its offspring, as well as the only one who can breed with genderless Pokémon at all.
It can breed with any Pokémon other than the Pokémon in the Undiscovered group and itself [...]
In other words: It cannot breed with Pokémon of the Undiscovered Egg Group, to which most legendaries belong, or other Ditto.
Note that Ditto belongs to its own egg group.