both these relative pronouns mean “that’. They can never refer to a PERSON (USE QUI). WE USE THESE WHEN YOU REFER TO SOMETHING THAT HAS NOT BEEN IDENTIFIED.

Ce qui is always followed by a verb form ( it is the subject of that verb); ex: Tu as vu ce qui est arrivé?

Ce que is always followed by a noun or pronoun +a verb ( it is the object of that verb); ex; je sais ce que tu vas dire!