What do i need to put on my i-864 since i got no tax return.?

as a petitioner, you have to file the I-864, and show whatever your personal income actually was with W2s. if you live at home with your parents, they'd both file I-864a's, as they are both members of the same household. your parents would have to file their tax statement. you would need to include a signed statement on why you didn't file.