Here is a short tip for beginners.
M-<DEL> to delete (“kill” in Emacs terminology) back to the start of a word, and
M-d to delete up to the end of a word.
C-x DEL to delete back to the beginning of a sentence, and
M-k to delete forward to the end of a sentence (we already covered moving by sentences and how Emacs defines a sentence).
Finally, refer to this post about deleting a whole line.
Note that all of these commands put the text in your clipboard so you can paste it elsewhere.