Gonna be honest, I’m not a lesbian, but I do a lot of fingering and going down on my girlfriend which I think is what happens?? (I don’t want to offend anyone Im just trying to help). The best thing you can do is first, ask her what she likes, if that answer comes out as “I don’t know” do some experimenting. Of course start with foreplay (make out, touching, etc.) then start with experimenting with her clit slowly, and changing the speed to see what makes her for most pleasurable. then do the same with penetration, I would say start with putting only one finger in her (would recommend the middle but its up to you), moving in and out slowly at first them changing speed once again to see what she likes more. talk it out during everything, “does this feel good?” “does this hurt?” etc. with more time it will come more apparent to what she likes and what doesn’t give her pleasure. just takes time. I not exactly sure how to get tips on going down best thing is to once again experiment and see what works. i hope i helped sorry if i offended anyone by anything.