I think that the first step would be to decide the type of discursive piece to write. For instance, do you intend to write a speech, or are you more interested in something like an-essay type discursive response, a travel blog etc.? Once you have done this, you can then think of the topic that you would like to explore that is consistent with fulfilment in modern-day society. Fulfilment in modern-day society sounds quite interesting and there may be different ways of approaching it. For example, you could discuss your experiences of visiting countries far from each other, not only in terms of their geographic location, but also their economy and culture. This can subsequently lead you to discuss the different perspectives that each country has regarding fulfilment.
You could also complete these two steps in the opposite order, that is, you can first think of the topic that you would like to discuss in terms of fulfilment in modern-day society, then decide on the type of discursive that would be most suitable to express your ideas in written form.
Generally speaking, while you should have an introduction, a body and a conclusion, you have some additional freedom when writing a discursive, as opposed to a non-Module C essay, in which case there is a stricter essay structure that you need to follow, such as PEEL body paragraphs. Based on this, you can control and modify the length and content of each paragraph as you see fit. You also have the ability to use first person throughout your discursive piece.
I hope this helps!