Cranial is talking about the BEC wire, the +5V that runs from the ESC to the FC along with the signal wire - not the main battery voltage wire from the PDB to ESC.
As for Naze alternatives - the KISS FC is probably the most beginner friendly, and almost everyone that I've heard of running them loves them. If you want to stay in the Betaflight family the SPF3 and it's clones are pretty solid. None of the Beataflight boards are any more or less beginner friendly, the firmware is the same and they all wire up essentially the same, just with different labels on the pins really. If you want to maximize your learning potential, Betaflight is the way to go.
So should i remove both positive and negative from esc and leave just the signal wire?
I have placed a order for SPF3 and kiss FC will keep you inform of the progress. Thank you all for your time and help.