Hi @ryouma17 glad you love the Sims :) and there are plenty of other straight males here too.
Cis is short for cisgender. That means that the gender you were assigned at birth, your anatomy, your pronouns, your personal sense of what gender you are, and the gender others tend to perceive you as, all match.
I am a cis female. Sounds like you are a cis male.
Gender fluid means that one or more of those aspects of gender is not exactly either the typical male or female.
(If it's just the anatomy that's not exactly the typical male or female, usually people use the term "intersex" instead.)
Pansexual is like bisexual, except the word emphasizes the ability to be attracted to people who are trans or gender fluid or nonbinary. Pansexual is a newer word, so there are plenty of people in earlier generations (like me) who describe themselves as bisexual because that's the word that existed at the time, but they do also fit the definition of pansexual. Using the word bisexual isn't intended to rule out people who aren't just male or female, it is just an older word.
Asexual means little to no interest in sexual intimacy. People who describe themselves as asexual might also be aromantic, or not.
