I'll attempt to expand on the other comments. Yes, Q is the 17th letter of the alphabet. Great, so now you see the symbol. What does it mean? That's more complicated.

Trump made many references to 17 and the letter Q throughout his presidency. Typically, that serves as a marker to identify that whatever topic he's talking about next is related to the Q concept. Great, so what's that? Q's main premise is that the world is controlled by a handful of so-called "elites" who are abjectly evil and who use that power to control people's minds, pacify them, and rule over them. As an extension, they abuse this power to make others suffer either through forcing people into poverty or through outright evil, specifically child sexual predation and child sacrifice. Trump got into the presidency and used that power specifically to disrupt their control structures and give power back to the People - not just of America, but worldwide (which is why you frequently see Q posts showing patriots rising up around the world). That's the Q premise.

Any time you deal with Q, you have to understand that the entire thing works by communicating through symbols. This concept is very, very old. Egyptian hieroglyphs were symbols. Symbols communicate meaning in millennia-old religions, and often with layers of meaning attached to the same symbol. The Phoenician numbers that eventually became the Latin alphabet we use are symbols. Numbers are symbols. Shapes can signify numbers and themselves become symbols. You can spend a lifetime trying to unpack the layers of meaning attached to some of these things. Freemasons do. Jewish Kabbalists do, which is where we dive into numerology and gematria. And interpreting it is difficult because of these layers of meaning. People can easily go in the wrong direction, and really the message only becomes clear after something has already happened (also a central Q premise - the news unlocks - that is, we'll see Q was predicting something abstractly, then see the results on the news).

While there's a TON of stuff in the 4600 or so Q posts, the major themes are: giving democratic control back to the people and stopping the child abuse. In this particular case, the issue is democratic control. Hypersonic missiles are intended to scare people into submission and into running to government and handing over egregious amounts of money to the MIC (Eisenhower's military-industrial complex) to buy "protection." Trump's saying he has weapons in place to protect us. Go live your lives freely. The double meaning is also a threat to the Deep State, but that's a larger discussion =)

Keep asking questions! Then use discernment regarding whether or not to believe the answers. I could be wrong, as could anyone else. You do your own thinking and find the wisdom you can be sure of. A core principle of thinking is that any belief you claim, you should be able to explain why you believe it. If you find that you can't, you need to discard that belief and look for a better explanation - that's discernment - a path to weed out the BS and find truth.