First off are you a hero? If you're a hero then you can get to the Watchtower through any safehouse/police station. There is a teleporter in each one that will bring you to the Watchtower. If you're a villain then you want to go to the Hall of Doom, which you can get to through any safehouse/night club. Once you're in WT/HoD just look for a teleporter to Anti-Matter Metropolis. I don't know where it is in the Watchtower as I'm a villain, but if you're a villain it's near where Kalibak stands in the central area of HoD.
As a new player you should also have a teleporter consumable in your inventory..put it there where you drink the soda. Use it and you get teleported into the watchtower...or villain side Hall of doom.. By the way..when your lvel 30 you can press the character advanced so you will get a free boos to cr 100
Quickest way to find it, go to your map and choose the button that says HQ. Then find the portal to the anti-matter zone and go to the vendor. This collection piece costs 20 qc and the completed collection gives you 5 MoV and a title ( 50 feat points too but that's the only thing worth completing it for).
