Suggest, lets get one ESC/motor going first and then move to the second. Put the Y lead to one side right now.
You need to put the 3 wire connector from the ESC into your receiver (correct way around), connect up the battery to the motor and see what happens when you operate the Transmitter - I assume the Tx and Rx are correctly bound?
The ESC default settings from Turnigy should get things working.
Once you have one working, move to the second. Put the red wire back into the second ESC, remove the first system and try the second.
If they both work separately - progress!
Would now reprogram both ESCs to the settings you think might suite your application best. They are in that article.
Once all works separately, remove one ESC red wire and tie back. You can then put both ESC connectors into the Y lead and fit to Rx. One control should operate both ESC/motors.
However, from my experience, if you have several Tx/Rx channels better to put each motor system on its own separate channel and do not use a Y lead. This allows individual motor control, which makes the boat easier to handle.
Might be better to now put these questions on the full site now so others can contribute, I have been known to make mistakes - which is why I ALWAYS fit fuses! I wanted the PM to send those instructions as am not sure how widely available they are.
Brushless are a challenge, but they do work well. a