Mr Cashman 23

I'm 24 years old now, had one credit card (and they gave it to me when I was seventeen) with a $200.00 limit, used the card and never paid it. Now almost 7 years later I'm trying to fix my credit, my credit score is 549 with equifax, transunion and expierera and the only deliquency on my report is that credit card and they put that on my report in the year 2000, will this go off my report ever? should i pay it? how should i rebuild my credit?

thanks for your help