The name speaks for itself.

I am relatively a new guy here and i would like to know how can i make an own map. Is it a premium thing or what?

Best place to start is the Help section (just click on the tab that says 'Help' at the top left of your screen). Read through that and you'll get a pretty good idea of what's involved in map design and publishing. And to answer your other question, every standard member gets to try out the board designer for their first map. After that, you need to purchase a premium membership.