A better way to read books for those times when the real world is too distracting.
To run on Android you need to do a bunch of things to get your phone setup as a developer and to generate creds. Best to just google the current best way to do this in the future. https://docs.godotengine.org/en/stable/tutorials/export/exporting_for_android.html
cd ~/Downloads/cmdline-tools/bin
./sdkmanager --sdk_root=/Users/edromano/Downloads/cmdline-tools/ "platform-tools"...blah blah blah
# Install OpenJDK 11
mkdir ~/.android
cd ~/.android
keytool -keyalg RSA -genkeypair -alias androiddebugkey -keypass android -keystore...blah blah blah
Editor > Editor Settings... > Export > Android
Android Sdk Path: /Users/[my_name]/Library/Android/sdk
Debug Keystore: /Users/[username]/.android/debug.keystore
Project > Export > Add... > Android
Release: /Users/[username]/.android/debug.keystore
Release User: The one you set when creating the keystore (ex: androiddebugkey)
Release Password: Same (ex: android)
Unique Name: Probably best to customize this like org.my_org.$genname
Warning/Error about "templates missing": Click the link to have Godot download them for you
Then just close. No need to actually export at first. USB debugging to phone should pop up an Android icon in the upper right corner of Godot when a phone is connect.
https://docs.godotengine.org/en/stable/tutorials/export/one-click_deploy.html
Debug > Deploy with Remote Debug
Project > Project Settings… > Input Map
Add a new input with a unique name
Click the + next to it and set it as Mouse Button > All Devices and Left Button
Now you can add a _input() that listens for something like Input.is_action_just_pressed("click")