I got a tao tao t125 and the carb and all lines were disconnected. I bought a new carb and want to make sure it's hooked up correctly. Is there only one line that goes from the tank into the carb? The line from the back of the motor (near the chain sprocket) what does that hook into?

 

That hose is most likely just a vent hose for the crankcase. On my son's 125, the open end simply points toward the ground. It isn't connected to anything. That may have changed since my kid's bike is kind of old, but most small engines will have that vent tube connected to the air box, not directly to the carb