RossMitchell

An important intermediate step in the setup is to see if you can load the file “readme.html”, if yes then a substantial part of your configuration is correct, if not then you have something to get right before even starting on the WordPress setup.
The 500 error on creating wp-config.php interactively is most likely just a file permissions issue, mostly I don’t bother fixing these on localhost because just accessing the files locally is easier.

Another approach:
– Have all of the different company WordPress websites use the SAME database in the same shared hosting account, have each use a different “$table_prefix” setting in their distinct wp-config.php file. This way each site remains independent.
– Put the shared event data into separate and distinctly named tables.
– Create shortcodes which invoke functions that query and display the event tables contents, this code is probably identical across all the sites, code could be in a plugin or add to child theme’s functions.php file, each site has its own copy of the shortcode functions. The queries used by the shortcodes name the tables in full.
– One site may have extra shortcodes which manage/edit the event tables, but could possibly give access to all sites.

The only drawback is that this design is not great security, the different sites share permissions on all the tables, they could interfere with each other. The also share the same cPanel account.

• This reply was modified 7 years, 1 month ago by RossMitchell. Reason: clarification, extra details

There are lots of membership plugins available here. Your club members will each have a WordPress account, the plugins have lots of options, I would be sure you will find one that is suitable.
There are also plugins that will let you migrate your members.

It can be done, several variations as to how.
Dione is correct in that you only have one setting for the site address and WordPress address in your WP settings, but it can mean different things to different computers depending upon where they are and how they are configured.

Configure your RaPi to have a fixed IP address on your LAN.
A) You have a permanently assigned and fixed IP address for your internet gateway.
Get a domain name or subdomain, set the nameservers to point to the router’s permanent IP address, set port forwarding to your RAPi, configure the WordPress to use the domain name in the site address and WordPress address. Configure the Apache server to use the “virtualhost” method, details here:
http://httpd.apache.org/docs/current/vhosts/name-based.html
B) You don’t have a permanently assigned IP address from your ISP, so use one of the dynamic IP solutions, otherwise similar to A) with a name that uses the dynamic IP service.

On your LAN, use the “hosts” file on each computer to map to the RaPi, including the RaPi’s “/etc/hosts” file itself, details on hosts files here: https://en.wikipedia.org/wiki/Hosts_(file)

Now computers on the LAN, and on the internet, all can see your RaPi server.

On the other hand, if your ISP has given you a permanently assigned IP, then ignore the virtualhost method, set the WP site address and WordPress address to this, maybe the router will still redirect LAN traffic using the port forwarding, even when the traffic comes from the LAN side.

If you want to put the menu into a widget area then you can put a shortcode into the widget which will activate your php function, you may also need to follow this article:

Enable shortcodes in widgets,
    from: https://digwp.com/2010/03/shortcodes-in-widgets/
	add_filter('widget_text', 'do_shortcode');

Of course if you wanted the menu to be in a page or post then you could put the shortcode in the page or post.

If the menu is not in a widget (or page/post) area then you will need to get into
the page templates, depending upon your theme probably in a file like “header.php”.
Be sure to be using a child theme, details here: http://codex.wordpress.org/Child_Themes

Sometimes I have taken a middle road, each of my category pages wanted a different sub menu in the sidebar, so in the child theme category template file I tested the category and chose a different menu to match, so in this case the menu was chosen dynamically but had static content.

Yes, this can be done easily.
I suggest that you look at how the “Beyond The Whiteboard” or the “exercise tracker” plugins work and customise them to your needs.
Create custom database tables to support your data, use either shortcodes or create page templates to activate your code, be sure to validate that your user is logged in and use nonce type session validation.

If I was doing this it would be with javascript, possibly with AJAX putting the responses into my database.

I guess it depends upon how much your time is worth to yourself and your client, $67 is not much in the scheme of things.