First, "Specialization" refers to one of many different tracks a trainer could take. For example, they could be a trader, a breeder, or a fighter. For a complete list with descriptions, click here
Also, Thunderbolt isn't one of Pikachu's egg moves. Please choose one from this list (also in the above link): Bide, Charge, Doubleslap, Encore, Present, Reversal, Wish.