If you can take a good pic before you plug in any power we could verify it for you.

Biggest thing is probably be sure you solder connectors on the esc for your battery with the correct polarity. The 3 motor to esc wires just plug them in any order... if the motor spins backwards, just swap any two.

esc connection to the receiver is likely channel 3 and the black wire on the servo connectors is ground and is usually the connector on the rx that is "down" or pointing away from the top, if that makes sense.