I am not a native English speaker and I have sometimes referred to people as male and female (as that is what I have been taught) but I have received some backlash in some cases, especially for the word "female", is there some negative thought in the word which I am unaware of?
I don't know if this is the best place to ask, if it's not appropriate I have no problem to delete it ^^
It sounds fairly scientific in a crunchy or incel way. As others have highlighted here, there are times it can be used, but generally, I'd stick to "women" or "ladies" for most situations. It flows better and avoids potentially negative connotations. That said, if english isn't your native language, I'd expect native speakers to cut you some slack; english can be a difficult language to learn, and the language is always evolving, particularly around gendered language right now. Sounds like you are putting the effort into learning it, though :)
Typically it does flow better, but I have a little mental stumble every time someone uses "woman" or "women" as an adjective. I know why they're doing it and I can't really fault them, it just... feels off.