Why Do You Need A Roofer?
Fixing your roof can be a difficult, time-consuming, and a dangerous job. Consider the disadvantages before you watch a video on YouTube and get to work. It may appear like a relatively simple repair, and to be straightforward, but there is a good deal of risk involved in this project.  And here are 3 main reasons why:
No amount of research will give you the same knowledge that experience can. You don’t want to experiment with your house — get the roof replaced the right way the first time to prevent more work from needing to be done. By doing it by yourself, you risk it not being done right and it will cost you even more money by eventually having someone else come out to fix the mistakes. 
Every project carries an unfortunate number of falling accidents; many in extreme injury or even death. Avoid these situations and stay safe. When you are learning a new skill, most of your attention goes to completing the task, not the situation surrounding you. In some cases this is okay, but when it comes to roofing, this is dangerous. If you do choose to take on this risk, be sure you have someone working beside you, to make sure you are safe throughout the entirety of the project.
Not only do professionals have the knowledge to get the job done well, they also work well with the tools that are needed to do it correctly and safely. Even though roofing is thousands of years old, the technology and techniques constantly change. Let somebody who has been through through it many times to complete the job. 
If you do it right on your first try, it may save you some money, but will take a lot of your time. Most people don’t know how to do a good job when they get on the roof and start. The time you spend may be of little return if you make even the smallest mistake.
For the major mistakes, it is necessary to call a roofing professional, which will cost you much more after having attempted it yourself. If the roofing company messes up, they will fix the problem, most of the time at no extra cost to you. When you make a mistake, you are left to pay for it. 
Before committing to your own project, consider all available options. Once you buy all the tools and materials, a roofing contractor doesn’t seem so pricey, especially when you account for your time. Be sure to do your research and choose the one in which you feel the most confident.
Warnings Before Hiring a Roofer: 
There are also different options that you could choose in opposition to a standard roof, solar, aluminum, or a "cool roof." The Department of Energy tells us that, "A cool roof under the same conditions could stay more than 50°F cooler and save energy and money by using less air conditioning." 
Only professionals will be able to properly give you a more custom roof like those listed above to help your house not only look more aesthetically pleasing, but continue saving you money after the purchase of their service.
LifeHack, "Why You Should Hire a Roofing Contractor Instead of Doing it Yourself", https://www.lifehack.org/articles/lifestyle/why-you-should-hire-roofing-contractor-instead-doing-yourself.html
Builder, "TESLA IS INSTALLING ITS SOLAR ROOFING PRODUCT IN EIGHT STATES", https://www.builderonline.com/building/tesla-is-installing-its-solar-roofing-product-in-eight-states_s
CBS Dallas, "Texas Roofing Regulation Bill Fails Again", https://dfw.cbslocal.com/2019/05/13/texas-roofing-regulation-bill-fails-again/
NBC 5 Dallas-Fort Worth, "4 Steps to Take Before Hiring a Roofer After a Hail Storm", https://www.nbcdfw.com/weather/stories/4-Steps-To-Take-Before-Hiring-Roofer-after-Hail-Storm--507631771.html
Warnings before hiring a roofer, ABC15 Arizona, YouTube - https://www.youtube.com/watch?v=F-5tBmpPYws
The Department of Energy, "Cool Roofs", https://www.energy.gov/energysaver/energy-efficient-home-design/cool-roofs