Nielsen hit it right on the head ... but i might as well ad to it ... it dont matter what engine you decide to use ... passion is key .. if there is a game you love to play (that is moddable) start there ... get some key skills in what ever area you what to get into (mapping, coding, animation and every thing inbetween)
this is just a hobby for me ... but it all started off as i wanted to make a game better
passion will take you a long way in life