Your English is fine - much better than my Portuguese
There are many ways to do this. One way is to just import all the text normally. Make three paragraph styles, and define the Next Style in each one. So FirstLine has the Next Style of SecondLine, SecondLine has the Next Style of ThirdLine, and ThirdLine has the Next Style of First Line. Then select all the text at once, then right-click the first style name in the Paragraph Styles panel, and choose "Apply FirstLine, Then Next Style."