You are not allowed to view this page -"I created the page!"

I have a website https://www.tnaarausa.com I need to duplicate this website and make a similar (exactly the same!) website. So what I did was, download the root folder and all of its contents to my desktop. Then made a copy went to the wp-config and entered the database and host information. I uploaded everything to the new site and at first it worked fine, even though the theme was not active and neither all the plugins. I activated the theme, and some of the plugins up until I was logged out and received the message: “You are not allowed to view this page.”
I went to the original site I’m trying to copy and noticed that in order to access the dashboard on that site you have to type in https://www.sitename.com/wp-login.php instead of https://www.sitename.com/wp-admin
I thought it was one of the plugins I activated but then I deleted the plugin folders and still no luck. I’m logged out of my site with no way to access the dashboard =(
This is the new website I cannot access https://www.tnhra.com