This is a step by step install on a base Ubuntu. This is the easiest way for me to set it up. If you know an easier way, please comment below. Before you begin, type in the terminal:
sudo apt install default-jdk git curl libc6:i386 libncurses5:i386 libstdc++6:i386 lib32z1 libbz2-1.0:i386
To avoid installing the Android Studio completely, you can simply set environment variable for Java. After the below, you can skip the part about installing the Android Studio.
Open the hidden file called .bashrc.
At the end copy and paste: JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/bin/java"
If you run Flutter in a virtual machine, such as KVM, VirtualBox, or VMWare, you will not be able to use the AVD. in that case, you could plug in your smartphone into the computer, but I could not do that for these videos.