Yes, you can be "goofy and vulnerable" acting and still get sisters to be attracted to you. Even as I sat in a a dialysis center laughing out loud at some goofy stuff on the internet, and looking the way I do, I had women asking me how pretty did I think they were, singing to me, telling me how good I smell, asking me if I was married, etc. For a lot of women it can be more about how you make them feel, than how goofy you are or how vulnerable you seem. Also, sisters can be just as goofy. You both can be goofy together, laughing and everyone wondering why you are but also see you both as relationship goals.
You don't have to mask who you really are to pull Black women, all you have to do is be confident and talk with them. If they are feeling you, you will know it by their body language. So you know to keep pushing forward. If they are not feeling you, you will notice that too by their body language. So then just move on. Sisters are human too, so they come in all sorts of mentalities just like Brothers.