What is the difference between pansexual and bisexual?
Pansexual means you are attracted to people regardless of gender.
Bisexual means you are attracted to two or more genders, including your own. (Bisexuality does not exclude trans people or non-binary people, especially since binary trans people aren't a third gender)
The differences are subtle, but they usually have to do with how you feel attracted, not who you think you are interested in. For example, bisexuals often prefer one gender. In contrast, still being attracted to others, or they think differently about each attraction, while pansexuals feel attraction the same way across all genders.
Queer is an umbrella term that encompasses all of the LGBTQ+ community. It can be beneficial for questioning people who only know that they are cishet or for non-binary people who don't have a relevant term for their sexuality because of their gender. But not all people want to be called queer because some people have negative associations with the word.