Hi @Gabriela_Higa You can still create sections when importing, please refer to the first Section (“Before you get started: tips to organize the data in your spreadsheet”) of this guide article: Asana CSV Importer • Asana Product Guide
@Leticia_Ghisio, here is how to import Subtasks: Asana CSV Importer • Asana Product Guide as long a you associate them to the correct task, they should automatically be populated in the Correct Section.
If you continue running into trouble, please reach out to our Support team with screenshots of what you’re seeing, and if possible share your CSB file, that will help them reproduce your issue and help you find a solution.
Hope this helps!