1.1. Upgrading to Stretch

Change text "jessie" to "stretch" in file:

sudo vi /etc/apt/sources.list

If you are planning to install gcc

deb http://mirrordirector.raspbian.org/raspbian stretch maincontribfirmware non-free

• NOTE we are using vi since we haven't yet installed ``` nano```

Run update and upgrade

sudo apt update && sudo apt upgrade