You need to learn bash scripting. Also, there are a few default files that the .bashrc uses which can be helpful to compartmentalize the custom things you do to it so that it’s easier to undo if you screw something up. To do that, just add this to the bottom of your .bashrc

if [ -f ~/.bash_custom ]; then
    . ~/.bash_custom
fi

What that will do is check if the .bash_custom file exists and then run the .bash_custom file in your home directory and apply anything in there. Also, you can call the file whatever you like, but bash does have some defaults that it will check for and run them without editing the .bashrc at all. It’s kind of hard to find a list of the the files that it automatically checks for, but I know that .bash_aliases is one of them, and I think it checks .bash_commands as well, but I’m not entirely sure. Either way, you can force it to check your custom one by using the code above.

Then you can create the file and add any custom things in there that you like. For example, I like to frequently update through the terminal but running sudo apt update && sudo apt upgrade && sudo apt autoremove && flatpak upgrade was a bit tedious and I wanted a bit less feedback so I made a custom alias for my personal use.

alias update='echo "Updating packages..."; sudo apt update -y &> /dev/null; echo "Packages updated."; echo "Upgrading packages..."; sudo apt upgrade -y &> /dev/null; echo "Packages upgraded."; echo "Cleaning up packges..."; sudo apt autoremove -y &> /dev/null; echo "Packages cleaned up."; echo "Updating flatpaks..."; flatpak update -y &> /dev/null; echo "Flatpaks updated."'

Which hides most of the text from updating and just gives me feedback on what it’s currently doing if I don’t really care to know all of the details. So now I just run update in the terminal and plug in my password and it updates and upgrades everything in a human readable way.

There’s a lot that can be done with bash scripting, like editing files, iterating over files and directories, setting environment variables. It’s basically a full programming language so the limits are mostly your imagination.