tips on first time wlw sex?

hi, i’m 22 and bi. i’ve been talking to this girl recently but i’ve only been with men since i have a very homophobic family. it’s nothing serious but she invited me over and i know what will end up happening since she’s very open about what she wants. do you have any tips for someone who has no idea how it will work with another woman? i’m especially nervous about going down on her. what should i/should i not be doing? please help a gal out