For some reason apache can't be started (despite the syntax is okay in the configuration). It's very likely another process is using the port 80.
You can check what processes are running using the command (
sudo netstat -tulpn | grep LISTEN). For instance, in the example below, the process with PID 4667 is using the port 80:
$ sudo netstat -tulpn | grep LISTEN
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 5622/mysqld.bin
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 469/sshd
tcp6 0 0 :::33060 :::* LISTEN 5622/mysqld.bin
tcp6 0 0 :::80 :::* LISTEN 4667/httpd.bin
tcp6 0 0 :::22 :::* LISTEN 469/sshd
tcp6 0 0 :::443 :::* LISTEN 4667/httpd.bin
To stop that process, you can use the command (
sudo kill). In my example:
$ sudo kill 4667
Could you do the same to ensure there's no process using the port 80 on your server? Once you do it, restart Apache as I indicated previously.