Can someone help me understand exactly what the term means? I'm fairly new to all of this and still a little confused
In my experience, queer has been kind of a blanket term used for and by anyone who's orientation or gender deviates from the norm. Like most terms of this nature, it was and is still used derogatorilly, but again like most other terms the LGBT community has pretty much succeeded in making it a word associated with pride. I refer to myself as queer all the time and love it, although everyone has a different perspective on this.
I've used it as ATtappman has. Just to describe anybody LGBT. Sometimes I've heard people not quite sure how to identify describe themselves as queer. Sometimes you'll see people use the term LGBTQ, the q standing for both/either queer or questioning.
Some LGBT people ID as queer because straight/gay/bi/ace doesn't really fit them. Some people use it as a blanket term for everyone LGBT (that's really controversial though). It's also widely considered a slur, but not in all cases.