How To wire FSESC6.8 with 6384 and other questions

Hello !
I received my Flipsky 6384 motor and IP68 FSECS6.8 ESC.
I had two or three questions about the assembly.

First, there is no keying on the motor cables and I cannot find the Indications on the wiring between the ESC and the motor. I would tend to believe that the middle cable is for information and the outer terminals for + and -, but is there a direction to follow?

Second question, but not the least. What battery can I order knowing I don’t have what to make it myself? And where preferably?

Finally, the ESC is waterproof with an aluminum shield, but I have serious doubts about the heat dissipation. There is no watercooling on it like the old model that I see on a lot of DIY videos. Should I plan to leave it submerged, or is the heat produced relatively controlled and I can just bridge a slightly larger heatsink into the case where I’m going to store the battery?

Thank you thank you to those who can enlighten me.
Have a nice day everyone.