Setting up any unix-based computer as a webserver is very easy - Apache on unix runs over half the world's websites. Configuration interfaces range from the command line to Apple's Server application.
But that's just one link in the chain. People have to reach your website for it to be useful beyond your desk.
I don't have any knowledge is networks or advance computer systems
That's a problem. you will need knowledge of networking, co-operation from your internet service provider (doesn't need to be active co-operation, they basically have to not block it), A DNS setup that allows for a changing IP address and a few other things.
Or you can pay someone to do all that for you. The webhosting market is huge, prices range from $1 / month / site and up, depending on your needs. Start there to get the basics under control, then later work on running it yourself.