DzMehedi For
[25-Dec-2016 15:21:06 UTC] PHP Deprecated: Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini and use the php://input stream instead. in Unknown on line 0
It would be best to get in touch with WordPress community forum to see what they can help you about it.
As for:
[Tue Jan 03 02:30:14.656445 2017] [:error] [pid 191054] (12)Cannot allocate memory: [client 66.249.79.167:28178] couldn't create child process: /opt/suphp/sbin/suphp for /home/arvixsof/public_html/index.php
You're going out of the memory, you can get in touch with our support for increasing your RAM allocation.