I’m guessing you want to selfhost, rather than use a hosting service?

When you say you have your site already, do you mean it’s hosted on a local webserver, or just that you have the files?

If it’s just the files, you’ll need to choose a webserver. I like NGINX myself, but lighttpd is another option (there’s quite a few options, really, but sticking to a well known option is generally more secure).

Configuration will depend on the server you choose, but then you’ll put the files into three “root folder” used by the webserver. This isn’t the system root ( ‘/’ ), but a different folder specified as the root of your web page, usually ‘/var/www/html or /srv/www/html’.

Once the files are in place, you can test the site by using the web browser on another PC and entering the local IP address of the server. If everything looks good, you can set up port forwarding on your router to forward public port 80 to port 80 on the local server.

Lastly, you will need a DNS provider which will point your domain to the IP address of your router. Assuming you have residential service, you will need to determine whether your IP address is static or dynamic, or if your ISP is utilizing CGNAT. Depending on those factors, you may need to do some additional setup.

Once it is working, your next step will likely be to set up SSL and port forwarding on 443. That will allow your website to be accessed over https, which is the standard for the modern Internet.

I have hosted my own website and a blog for a while, and there are definitely some additional steps I would recommend to take, but the above is your basic starting point.