Ok, basics time:
Your gender is who you are (male, female, bigender, agender,...). Genderfluid technically isn't a gender but the description of someone having more than one gender and might experience each of them more or less at different times. Transgender is also not a gender, it just describes that the gender you identify with is not the biological sex you were assigned at birth. This has nothing to do with who you feel attracted to.
Your sexual or romantic orientation is who you are attracted to (heterosexual, homosexual, bisexual, asexual, pansexual,... - or all of those but with the ending "-romantic" for romantic orientations). This is not about yourself at all (although identifying as lesbian kinda implies that your gender is somewhere on the female end of the spectrum for example). You could argue that asexual is not actually a sexual orientation either but a description of the intensity of your attraction which is why some people on the asexual spectrum add another identifier to signify that they are attracted to some people but a lot less than most others.
If you also want an explanation for the difference between romantic and sexual attraction just tell me. 😉
