The familiar sights and sounds of children and families talking and laughing as they munch on pizza and sip soda returned to Fierro’s Pizza last Thursday. Al Fierro, a co-founder of the pizzeria, which opened at 104 Park Place in East Hampton in 1983, was back behind the counter, along with Stephen Hickey, his new business partner. A portrait of Mr. Fierro’s father, Albert Fierro Jr., looked down from a wall by the counter and a Yankees preseason game played out on the television overhead. All was right in this little slice of the universe.