New to Server Configuration - How does it all Work?

Hello all, I am new here, this would be my 2nd or 3rd post, I am also still browsing the entire forum, there is a lot to look at.
I was happy to see this topic and thread,
All though I do have account with a paid hosting ,and a domain, I have reached a point in my life, where I am seriously thinking about making the investment , of both time and money, to set up my own server, do my own hosting, possibly once I get the hang of things, I may consider start offering hosting to others, but that would be further down the road.
Something I wonder about. I have a “server”, I have been using to experiment a little, LAMPP, just the other night I tested it, and a friend that I trust , connected using the IP I shared with him, when I am ready, to actually put the server online, full time, to start just hosting my own site/forums, I would prefer to be able to use a URL, address, with names, instead of a IP, example: right now, I had to use

http://00.000.0/test.img

( the IP number, not 0s really), Ok , he connected just fine to the image, just using:

http://00.000.0

He connected to the index.html just like anyone would, So how do I make it where, instead of the IP number it would be something like,

http://www.MYHOMESRVER.com

(this probably would not be the name, but is for a example) I would probabley use the domain name, I have, I realize for sure, one would need to be carefull and not start using some other sitename or domain name that is owned by some else, I am wondering how all that works. Hope my question makes sense. I am not very good with words, etc, so it sometimes is hard for me to word my questions
Thanks

You need to register a domain name. The registrar will have a control panel where you configure the domain settings - in there you can point the domain to your IP address.

Ok, thanks on that, so I could just use a domain name I all ready have.