This might be useful in battery-powered equipment, to show data like when a battery was last fitted, and how much estimated battery life is left. This will remain on the screen even after a battery has died. There are situations where a dead battery can result in a dead user!
That should be enough to get on with. The level shifter is for interfacing to 5V devices.
2020-10-27 Setting up R-Pi with fresh installation of Raspbian on Micro-SD card.
Had some issues with this. Installed Raspbian and Kodi from the NOOBS card. After updating itself, Raspbian fails to boot, producing repetitive 4-flash sequence on green LED, indicating it cannot find the loader program. I used the Windows Raspbian disk-image creator, which produced an SD card that booted reliably.
Second issue is that my display (Dell) goes blank every few seconds. Google results suggest this is due to inadequate earthing of the monitor. It looks fine to me. Other results suggest changing the HDMI drive boost settings of the Pi.
I guessed that the USB PSU could not supply enough current, and thus the Pi failed while re-writing the card. I have replaced it with a bigger PSU. Swapped displays - my LG 2753EV does not blank.
2020-11-02 Set Locale Country and Keyboard to GB. In Settings-->Configuration-->Interfaces tab, enable I2C and SPI.
Run Thonny IDE interface for Python. Ran the example program LED.py and this seemed to work.