Development is about creativity and exploring ideas in different ways.
Development is about selecting ideas, visual elements, compositions and techniques from this initial work and using them in new ways.
It is important that you don't become too attached to your first idea.
Don't worry if the work you produce seems unresolved and isn't perfect. It is an important part of the creative process to try out new things and to make creative decisions based on what works and what doesn't.
And don't worry if you try something that doesn't work. Showing creativity is more important at this stage. Remember you can refine your work and produce a more finished result for the sustained project in your portfolio and your assignment.