You start with an element, it can be a main element and give it an id="main, and then you put the rest of your code, all the other elements inside this main element.
What about this do you not understand?
Do you understand what an HTML element is? If not, when you searched what did you find that you didn’t understand?
Do you understand how to add an attribute to an element? This was something you did a lot when doing the lessons.
Please, the more information you give us, the more likely we are to be able to help.
You need to learn how to better explain your problems so you can get better help.
if you don’t know how to create the project (it’s explained on the challenge), you need to go to the bottom of the page and click where it says: using this code template