"When I press ""Enter"" after entering the command in the terminal, only "">"" appears repeatedly."

I think the secondary prompt is displayed.
Command input is not complete and waiting for input.
If you press Ctrl-C (C while holding Ctrl), the input will be canceled and you will be back to the original state.

That's what happens when you forget to close the quote. Check for errors in the commands you entered

Example)

 $echo "hello world←Press Enter while forgetting to close the quote
>← Incorrect input condition as the quote is not closed
>
>" ← Command executed when quota is closed
hello world