Server internal error after redirecting domain

Hello,

I am stuck and really need some help.
I am encountering an error page when I go to my login page ( https://motifmediagroup.com/wp-login.php ) and my site’s content is not loading properly ( https://motifmediagroup.com/ ).

These problems came up after I went through the process on this web page ( https://codex.www.ads-software.com/Giving_WordPress_Its_Own_Directory ) to change my site address’ URL. I am not sure where the problem is and have retraced my steps several times. Does anyone have a solution to this? Any help would be greatly appreciated.