After performing a research, even if it's a negative result, scientists communicate to their colleagues and the society their results. They can do it by writting articles that will be read by other people, by performing oral presentations, but usually, they design a scientific poster where their goals, methods, results and conclusions are exposed and during the Poster session, their colleagues can ask them about their results in front of the poster.
It will have the standard scientific format, with the following sections:
To help you with your work, you can download the Template for Scientific posters.and read the criteria that will be used to asses your work: the Rubric for the assessment of Research Posters.
Invite your parents, students from other classes or visitors from your town or city, to come to see your posters. Stay next to your poster and answer the questions you get about your work.
Here you have some indications to organize a Scientific Congress at your school (in catalan).