You have to be careful when exposing your server to the internet.
You need an external IPv4 address. If the IP address is not static you also need a domain name and a dynamic DNS service that can link your domain name to your IP.
Then you need to add port forwarding to your router.
If you want to go that route, I would suggest to run your website in docker and use letsencrpyt to get a certificate for your host.
Here is an example for nextcloud, but you can also add another nginx or wordpress docker to it.
I have already configured nextcloud on the NAS
and i also have a duckdns address for the nextcloud.
I want to create another domain for my presentation site for my work
but my doubt that I'm going to create conflicts between nextcloud and my website
also because I'm not a genius like you, on these things