A shell script is a text file that starts with a shebang, the shebang tells the OS what shell to use to execute the script
#!/bin/bash
# My first Script
echo Hello World
chmod 755 my-macro.sh
./my-macro.sh
Create this file with a text editor like gedit (or if you like punishment vi)
Give the file you created execute privlidges
https://www.linuxvasanth.com/learn-create-static-dynamic-bash-shell-script-file/