Presenting your projects at Science Fair gives all of us a chance to learn about your work, and to congratulate you on a job well done. Science begins with curiosity. Good science projects spring from questions and ideas you have about your world. Almost anything can be the basis of a good project, if you find a good question to ask about it. Start with something you are interested in.
Science is a way of asking and answering questions.
Different questions will need different kinds of observations, experiments, and procedures to answer them, but all involve carefully thinking about how what you do is helping to answer the question. The more care you take in thinking about your experiment, the better your answers will be. A procedure that gives you the results you need to answer that question. Repeated trials, to demonstrate that your results are not just due to chance. Once you decided that, you would know whether your procedure should include measuring sprout length while they grow, or performing taste test after they are done.