Help – Website inaccessible – server 500 error

did you change anything before this happened?

Just editing tags on posts

try deactivating your plugins through FTP.
https://codex.www.ads-software.com/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F

I followed this:
or via FTP

Create an empty plugins folder
Via FTP or your host’s control panel, navigate to the wp-contents folder (directory)
Via FTP or your host’s control panel, rename the folder “plugins” to “plugins.hold”
Via FTP or your host’s control panel, create new folder called “plugins”
Login to your WordPress administration menus
Via FTP or your host’s control panel, delete the empty “plugins” you previous created
Via FTP or your host’s control panel, rename “plugins.hold” back to “plugins”

But it has had no effect.

Try checking your .htaccess file. Many times 500 server issue is caused by .htaccess.

htaccess file is empty. Should there be something in it?

Try to create one, refer to here:
https://codex.www.ads-software.com/Using_Permalinks#Creating_and_editing_.28.htaccess.29

But just to make sure you are sure you have insatlled WordPress correctly on your server?
Coz it doesn’t seem there’s the wp-admin location here
https://www.woodleighschool.com/wp-admin

yes, and the . in front is a crucial part of the filename. You might have to check your FTP preferences and make sure it’s set to show hidden files.

This should be in your .htaccess file.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

No – the wordpress dir is https://www.woodleighschool.com/wordpress/

I’ve checked the .htaccess file repeatedly and it is blank.

Does that .htaccess file go in the root or the wordpress dir or both?

As fonglh said above,
add the code in .htaccess file and put the file in the
https://www.woodleighschool.com/wordpress/

so the location of .htaccess file should be
https://www.woodleighschool.com/wordpress/.htaccess

Tried that but it has had no effect.

Can you check if there’s a .htaccess file on your root directory
located in https://www.woodleighschool.com/ ?

no