Sorry if the title is confusing but essentially what I want is to have standard text editor features like Command< to move to the beginning of the line or CommandShiftBackspace to erase a line. Is it possible to implement such stuff in the terminal interface? Preferably, I would not download a terminal emulator like iTerm etc..
There are ways to navigate in the terminal but they don't use the macOS keystrokes for navigation as the BASH shell actually predate macOS/NeXT. For example CtrlA moves to the beginning of a line and CtrlE moves the cursor to the end of a line. A quick search online on BASH shell keyboard shortcuts will yield a whole list like this, for example.
As an alternative BBEdit is a text editor that has been around on the Mac for ever. Way Pre-OS X. And one of the features is a command line window that acts much like a text editor and uses the standard Mac keybindings. But then you'll have to buy a programmers text editor to get the features you want in a shell window.
Might be best if you just learn the BASH keybindings, as that is lots cheaper ;-)
Apple has the complete (AFAIK) set of Terminal Keyboard shortcuts on their support website. It seems thay cover at least some of what you're looking for. THere's also an expanded set of topics relating to various aspects of terminal use that should be helpful.