Whenever a board is being changed by your mentor keep an eye out on what he's doing, ask questions.
They'll fairly straight forward once you've seen it being done and done a couple.
The tricky bits getting it looking spot on with the nice sweeping cables
I would be concerned about putting up a picture of breaking into the meter to put in a temporary supply.
By no means the perfect example however I'm quite proud of it
Earth to the earth bar, neutral to the neural bar. If it's a dual rcd be sure to terminate the same cable to the same side of the board.
Get yourself a cheap board as rpa said and give it a mock test with off cuts of cable.
Another tip:
When connecting up have say, upstairs sockets on one side and downstairs sockets on the other side so should a fault happen total loss of power to the house will be less likely to happen.
Best of luck