PR4100 webpage Wordpress

I didn’t need full blown Wordpress install but I installed because it was easy and I overwrote the index.php to run a static page. Is there anything I should do to make this setup more secure? I’m using it as an internal intranet directory so it’s not exposed to the internet.

Secondly what would I need to do if I wanted to map a domain to the Wordpress directory?

Thanks in advance! I’m not the worlds greatest Linux guru.