You would have to catch the 525 from stop number 16196 (not even a half a block from the hotel if you follow the road direction) to get to the nearest rail station(Southwest Medical Market District/Parkland). Catch the rail (the sign above it will be colored orange) in the direction of LBJ Central (the rail route will go south along the American Airlines Center then loop back up). Get off at West End Station.
I'll be honest here and say that if there are any smashfests in Arlington, you are likely screwed as the city doesn't have public transportation. However, if you want to go to Fort Worth, head South(sign says Westmoreland) one stop to Union Station. You will then transfer to a red white and blue train that will take you to Fort Worth. A word of warning, if you do decide to go to Fort Worth, train tickets are $10 for the day that must be purchased at the point of origin, and that will allow you access to Fort Worth's service as well.
Plano boys usually do smash fests, but it is mostly Melee. If you decide to go to Plano, head north (Sign says Parker Road Station) from West End station on the RED line.. If you hop on the Blue line, it will take you to Garland.