We probably won’t be able to help you unless we can see your HTML.
To display your code in here you need to wrap it in triple back ticks. On a line by itself type three back ticks. Then on the first line below the three back ticks paste in your code. Then below your code on a new line type three more back ticks. The back tick on my keyboard is in the upper left just above the Tab key and below the Esc key. You may also be able to use Ctrl+e to automatically give you the triple back ticks while you are typing in the this editor and the cursor is on a line by itself. Alternatively, with the cursor on a line by itself, you can use the </> button above the editor to add the triple back ticks.
“…within each div.question-block element, add one p element with text of incrementing numbers, starting at 1,”
This means the p element in the first div should have the text 1 and the p element in the second div should have the text 2. There should be nothing else in the p elements. And what is the purpose of this on the p elements?
“…and one fieldset element with a class of question.”
It is implied that the fieldset will come after the p element, not within it.