Need Washington DC metro help?

I'm going tommorrow to the Washington Nationals game I will be going to the Franconia/springfield station I know I'll be starting on the Blue Line and then getting off at Pentagon and getting on Yellow Line and then getting off at L'enfant Plaza and getting on green line and getting off at navy yard my biggest question what do i do about ticket fare is their a unlimited option? please help any tips will be appreciated... I have been on Metro before but I was so young and I didnt handle any of this.