Hi,
Please check your htaceess file.
Make sure it looks exactly like this:
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
If that doesn't help, rename your plugins folder to plugins-old, and make a new folder and name it: plugins
see if your website works. If It does > first thing, head to your admin panel and go to plugins section you will get a message that all plugins are desactivated > at this moment start moving all folders inside /plugins-old/ to /plugins/ folder > refresh your admin page and activate the plugins one by one until you figure out the one that is causing the issue