404 documentation error

Hello,

I constantly get a 404 documentation error. Somebody tried to help me giving me this answer:

Make sure that you have .htaccess file in your main wordpress folder.
If not, please create one and insert the text below in it, with your folder name
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /your-folder-name/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /your-folder-name/index.php [L]
</IfModule>

I don’t know where i can find the main wordpress folder and what supposed to be the folder name. Can anybody help me out?