What do you mean by..this..anyone answer this pls(No ex post facto law or bill of attainder shall be enacted.)

The answer above is correct as to the ex post facto part of the question, but omits the bill of attainder explanation. A bill of attainder is an act of a legislature that declares that someone or a group of people have commtted a crime and should be punished. They're unconstitutional in the United States.