Depending on the image selected you will need up to 8 GB SD cards.
Thi is not a mandatory step but if you want to have the confort of remote accessing your developement or operational computer remotely, you will have to enable sokind of remote access solution.
Fortunatly, the Raspberry Pi comes already with a number of solution installed.
RealVNC https://www.realvnc.com/en/raspberrypi/
Use the raspberyy configuration tool
sudo raspi-config
in the Advanced Options > Resolution, and choose an option.
https://www.realvnc.com/en/connect/docs/raspberry-pi.html