Fatal error: Namespace declaration statement

When continuing after entering hostname and database information I get the following fatal error.

Fatal error: Namespace declaration statement has to be the very first statement in the script in /home/content/83/2392383/html/wfxstore/system/library/db/mysqli.php on line 3

I'm not a coder. Mostly rely on plug and play types of installs. How can I fix?

Well, always check on Google first, it's not an OC specific error message,
rather related with a PHP Version and/or Server setup, you try to use.
And OC is not all just plug&play, it takes some Wisdom, to succeed !
Good Luck
Ernie
https://www.google.com/search?q="Namesp ... statement"