I took over the company’s website server halfway, but the website could not be accessed after restarting. The system is linux CentOS 6.5. Can you tell me where it is

  linux, question

The server uses Aliyun’s ECS system and linux CentOS 6.5.
After restarting the server once, there was a problem that the website could not be accessed. Later, I tried to open the web service by looking at relevant articles from the internet, but 502 reported an error.
I don’t know anything about linux. I asked my friends for help, but he couldn’t help it without the environment deployment files of the server. I only have a few accounts and nothing else has been handed over to me. I don’t know if there is any way to solve it. Worship the great god ~ ~ ~

Should be FastCGI process did not start
Execute services php-fpm start