Do you mean delete your Steam account? If you are playing in SSL2, then you cant. If you mean delete your Steam account, then contact the Steam FAQ. It might be possible.
Official Steam support page: https://support.steampowered.com/ You're not able to remove your account. Even so, you'd basically be losing all of the games you bought yourself so it's pretty idiotic to remove it unless you're a f2p. This could help by a bit: https://support.steampowered.com/kb_article.php?ref=1558-QYAX-1965 Or just make your account completely private and create another one.
Thank you nobody seems to have gotten what I said To really dumb what i said down, How does one contact words? >.>