That looks too literal to me. I’m also not entirely sure 何物 is really used all that often - I don’t think I’ve seen or heard it so far.
A phrase I’ve heard is 言いたい事がある (or あります of course) but I have no idea if that’s appropriate in a classroom setting. I suspect the right wording also strongly depends on what kind of announcement you’re looking to make, and how polite you’re going to be about it.
何か is the appropriate “something” for what you’re thinking of as “something”, but as noted by yamitenshi, it’s not necessary to include it. The 事 of 言いたい事 already has the “thing” aspect covered.
I’m only writing this because of what you wrote here, if it does not apply to you, you are welcome to ignore it, but I suspect it answer the not knowing anything part.
I don’t know if this is the first time you’ve tried to learn a foreign language but it seems to me (as someone the learned 5 foreign languages 2 at school and 3 on my own) that you’re learning the hard way and the results you get aren’t yielding the understanding and skill you are trying to develop (correct me if I’m wrong). It feels like you try to impose english on Japanese and that it’s created in a vacuum, instead of learning Japanese and using english as an aid not a source. I’ll try to explain:
If you use a free resource like irodori for example, you’re being exposed to the way Japanese people speak in everyday life. You see the phrases the way they should be, and the english translation services the Japanese and not the other way around - why? Because language has a cultural context and while you might want to express something in your own language and it make sense to you in the context of your own life/cultural context, the nuance you are looking for is not the way things are being expressed in that foreign language, so while the parts of speech you put together might seem logical they are not. And this is something that ai translation fails with a lot - intention and context. Also some phrases, words and sentiments don’t exist in english, you can explain their sentiment somewhat closely but not in a literal way. Trying to learn a language in a literal way will get you poor results.
Also kids learn their mother tongue they first learn by imitation. They don’t learn grammar but their brain recognized patterns over time. When learning a second language as an adult self learner it is usually more beneficial to seek an example for the situations you are trying to articulate either in a book or in a video. It exposes your brain to the language in a more organic way. You don’t need to invent the language or deconstruct it in order to learn it. At least not the basic stuff.
Errr… am I the only one here that feels in a middle of a Turing test on mushrooms with an ai that scraped too many snl memes and has an incel tendencies?