That depends on the standards set by your instructor or school. It also depends on how you are presenting any information you have lifted from other sources. For example, a paragraph-long quote that is properly sourced and attributed is not plagiarism. However, it may show up as content that isn’t original. On the other hand, if you steal a shorter quote, and pass it off as your own thought, without giving credit, that is plagiarism.
In many cases, you can find out what the expectations are. Sometimes, your instructor will publish the percentage of originality they expect in the assignment rubric. In other cases, it will be with the course rules.
Don’t forget to learn what will happen if you should turn in a paper that isn’t completely original. In some cases, the consequences could be failure or expulsion. In other instances, your instructor may simply wish to review your paper to ensure that you have given proper credit.