wp-admin not working

Hello,
Please go to your wordpress root directory in file wp-config.php and Enable WP_DEBUG by making its value true. So you can check what error is throwing.
To get more help please visit this link https://codex.ww.wp.xz.cn/WP_DEBUG

Thanks

Hello,
The error displays itself when there are:
Blank lines at the top or bottom of a document.

Too many spaces before, in between or after the beginning <?php and ending ?> PHP tags
There are too many unneeded spaces or blank lines in a specific part of a document
In order to fix the spacing issue, you need to first know where it’s happening. Fortunately, the error message lets you know which file and line is affected. Keep in mind that you may see this sequence multiple times on the page which means there are multiple files that need fixing.
Check unwanted space in your functions.php file.

Thanks