Failed to start httpd.service: Unit not found

It seems that you are encountering an issue with starting the httpd.service on your system. The "Unit not found" error message usually indicates that the service unit file is missing or not installed.

To resolve this issue, you can try the following steps:

1. Verify if the httpd package is installed on your system by running the command:

   sudo yum list installed | grep httpd

2. If the package is not installed, you can install it by running:

   sudo yum install httpd

3. Once the package is installed, try starting the httpd service again:

   sudo systemctl start httpd

4. If the issue persists, you can try reinstalling the package:

   sudo yum reinstall httpd

5. After reinstalling, attempt to start the service again:

   sudo systemctl start httpd

If none of the above steps resolve the issue, it might be helpful to provide more details about your system and any error messages you are receiving in order to assist you further.