Type in Gobus Canal Street and it'll put you right where you need to be. There is no physical address so to speak. You can also put in Roger Williams Memorial Park on Canal Street. I hope this helps.
I found Go Bus kind of rude, but I know you could type in megabus stop on Google Maps, that will show you. Oh yeah, you need to get online and make a reservation with gobus, I believe they have an app to download!
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