Basics - More Bash Scripting

You could start your learning here:

Reading Documentation about Commands

The Edx Link (Chapter 8)

• man COMMAND
• COMMAND -h or COMMAND --help

Quick Reference - Basic Commands

• cat,less,more to print files,
• head, tail to print only the two ends of the file
• grep "text" to filter the output of the stdout pipe (Ref)
• check network by ping,ifconfig,iwconfig
• check USB devices by lsusb
• check harddrive (block device) by lsblk
• check device messages by dmesg or dmesg -w
• check services by sudo systemctl status and similar command of start, stop, restart

.bashrc and .profile file

They are scripts that are automatically run by the shell when you open a new terminal. They can be quite useful in setting up environment variables like PATH, and running scripts.

https://serverfault.com/questions/261802/what-are-the-functional-differences-between-profile-bash-profile-and-bashrc