When you say “failed to start”, what do you mean exactly?
Do you see it running at all when using either top command or ps command? If not, you can start it via systemctl command.
Otherwise, you can maybe check the log file at /var/log/messages but I don’t recall if that’s where Apache sends its logs. There might be an apache folder or httpd folder in that same location though (for Apache logs).
Also, Apache won’t start automatically after reboot unless you tell Systemd (the service+system manager) to start it for you.