Hello, @Azager,
First of all, thanks for the login details.
Now, I Logged in to your site and checked your issue on the homepage I can see that it is a memory issue as you can see in the image: https://postimg.cc/jCq1HvXg in order to fix it kindly contact your service provider to increase the memory limit until your issue will be resolved.
Regarding the user login issue, I have checked it today and it is working fine as you can see I have created a dummy user on your site, and it login successfully: https://postimg.cc/BX4ncryW
Regards 8Themes Team.