First, connect to the pi using the USB to UART cable, following the instructions at Adafruit, and enabling the connection in /boot/config.txt
Then set up wifi following the instructions at raspberrypi.org.
Then change the default password using:
sudo passwd pi
Then enable SSH, and update the hostname using:
sudo raspi-config
# Select Interfacing Options and enable SSH
# Select Network Options and change hostname
Finally, update the software with:
sudo apt update
sudo apt upgrade