A research paper should be a combination of your ideas and the previous research of other scholars on the same topic. You can use another scholar's words, facts and ideas, but this borrowed material must not be presented as your own creation.You should be looking for sources that provide you with new information about the topic that expands or supports your ideas.
Reusing work you did for a previous assignment-- even though it is your own-- is also considered plagiarism. Seek guidance from your instructor if you would like to cite your own work.
It is your responsibility as a university student to learn and use appropriate research writing techniques. See the UWM Handbook for the official statement on Academic Misconduct.