How about making money from creating original, engaging, high-quality content?
Nevertheless, to answer your question: if the content you wish to use is copyrighted, you have to ask for written permission to use it. There is an exception from that, too - that is called ‘fair use’.

What is fair use?


Fair use is a legal doctrine that says you can reuse copyright-protected material under certain circumstances without getting permission from the copyright owner.
Different countries have different rules about when it’s okay to use material without the copyright owner’s permission. For example, in the United States, works of commentary, criticism, research, teaching, or news reporting might be considered fair use. Some other countries have a similar idea called fair dealing that may work differently.
Courts analyze potential fair uses according to the facts of each specific case. You’ll probably want to get legal advice from an expert before uploading videos that contain copyright-protected material.

Can I really make money using material from other people’s work?


The four factors of fair use:
In the United States, fair use is determined by a judge, who analyzes how each of the four factors of fair use applies to a specific case.

1. The purpose and character of the use, including whether such use is of commercial nature or is for nonprofit educational purposes

Courts typically focus on whether the use is “transformative.” That is, whether it adds new expression or meaning to the original, or whether it merely copies from the original. Commercial uses are less likely to be considered fair, though it’s possible to monetize a video and still take advantage of the fair use defense.

2. The nature of the copyrighted work

Using material from primarily factual works is more likely to be fair than using purely fictional works.

3. The amount and substantiality of the portion used in relation to the copyrighted work as a whole

Borrowing small bits of material from an original work is more likely to be considered fair use than borrowing large portions. However, even a small taking may weigh against fair use in some situations if it constitutes the "heart" of the work.

4. The effect of the use upon the potential market for, or value of, the copyrighted work

Uses that harm the copyright owner’s ability to profit from his or her original work are less likely to be fair uses. Courts have sometimes made an exception under this factor in cases involving parodies.