A prospectus is a formal proposal of a research project developed to convince a reader (a professor or research committee, or later in life, a project coordinator, funding agency, or the like) that the research can be carried out and will yield worthwhile results.
Choose a comfortable place in your local library where you are away from distractions and you can focus on the work that needs to be done. Try using the card catalog and computers available to make your search easier.
If you have two main points in your thesis, three or five main sections might not work for your research paper. If the assignment asks you to introduce a topic, explain different opinions on the topic, and then choose and explain your opinion, then your paper probably needs three main sections, one for each of those objectives.
Take what you have learned from a Google search or Wikipedia article and dig deeper. Check out the sources on the article, use keywords from your internet search to search an academic database, or ask an expert whether or not what you learned is valid and if it is, where you can find a reliable source stating the same thing. So, just to be clear: you can use Wikipedia as a starting point in your research, but you should not cite Wikipedia as one of the primary sources for your research paper.
If you want to find helpful and reliable sources of information, the library is literally the best place to look around. There are numerous books, published articles, journals and etc. that you can choose from about your chosen topic.