hello!! section elements are used to group related content! so, what they are asking for is: nest all of the elements that are in the main element, in a section element, so you can organize your code better!
If you have a question about a specific challenge as it relates to your written code for that challenge, just click the Ask for Help button located on the challenge. It will create a new topic with all code you have written and include a link to the challenge also. You will still be able to ask any questions in the post before submitting it to the forum.