It's great your friend is so supportive and you have to start somewhere if you want to progress your transition from "not ready" to "OMG what was I worried about". That said, if you do truly not feel ready then don't do it. You need to feel you will be safe and that your friend/s will have your back if it goes pear shaped.
Night clubs are a mixed bag depending on the crowd - invariably there will be someone who has a transdar no matter how passable you are, people are often drunk or hyper, it's easy to become separated from friends or not be heard. If you think getting a passable voice is hard, try doing it in an environment where you have to yell over music and other noise. Anyway, I know that comes over as negative, I'm not saying don't do it, just make sure you are safe and that your friend/s understand that you may need or want to exit quickly with them regardless of how much fun they are having. They need to have your back 100%.
Personally, I'd suggest you give it a trial run, even if it's just going down to the corner store and back just so you get a sense of how it feels for you, take the friend with you if needs be.
Have a fun, safe, time. Passing is often largely about presentation and confidence not looks alone,and judging by your avatar if you can get those first two sorted you will romp through this!
