Is it correct !
We lost my cousin Soufian when he was five years old, we were all at my grandma's house eating a lunch and he went out alone .
He was lost for two hours , but fortunetly my grandpa found him in the street and he was right [emoji][emoji]

Question

Answer

Nearly, but there are one or two things to fix. You can't run on another main clause after that first comma; you must either replace it with a semicolon or a full stop / period. You also need a full stop after each of your other sentences. "Fortunately" is spelled thus, and it should be "he was alright" rather than "he was right".