Need suggestion to fix website load time issue

Question

I want some suggestion to fix site speed problem i am using Apache and nginx need some configuration to fix load time issue My VPS specification

> 30GB Ram
> 2000 GB SSD-boosted
> 1 Gbit/s port UNLIMITED Traffic
> UP steam 120 Gbit/s
> Six cores Processor

I am using sentora(zadmin) web panel i am facing too much load time issue my server response is good but page take too much time to load i thing there is problem with my web panel configuration.

PING DATA

---   DIRECT SERVER IP DATA   ---
Pinging 173.212.213.220 with 32 bytes of data:
Reply from 173.212.213.220: bytes=32 time=279ms TTL=47
Reply from 173.212.213.220: bytes=32 time=277ms TTL=47
Reply from 173.212.213.220: bytes=32 time=278ms TTL=47
Reply from 173.212.213.220: bytes=32 time=278ms TTL=47

Ping statistics for 173.212.213.220:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 277ms, Maximum = 279ms, Average = 278ms

   --- IP BIND BY CLOUDFLARE ---
Reply from 104.18.60.166: bytes=32 time=147ms TTL=52
Reply from 104.18.60.166: bytes=32 time=147ms TTL=52
Reply from 104.18.60.166: bytes=32 time=147ms TTL=52
Reply from 104.18.60.166: bytes=32 time=146ms TTL=52

Ping statistics for 104.18.60.166:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 146ms, Maximum = 147ms, Average = 146ms

Server running on Cantos 6.9

Updated

error log

[Tue Jun 19 07:53:58 2018] [error] child process 4442 still did not exit, sending a SIGKILL
[Tue Jun 19 07:53:59 2018] [notice] caught SIGTERM, shutting down
[Tue Jun 19 07:54:00 2018] [notice] Digest: generating secret for digest authentication ...
[Tue Jun 19 07:54:00 2018] [notice] Digest: done

Apache httpd.conf

<IfModule prefork.c>
StartServers       16
MinSpareServers    10
MaxSpareServers   40
ServerLimit      1024
MaxClients       1024
MaxRequestsPerChild  4000
</IfModule>

<IfModule worker.c>
StartServers         4
MaxClients         300
MinSpareThreads     25
MaxSpareThreads     75 
ThreadsPerChild     25
MaxRequestsPerChild  0
</IfModule>