I don't know how to come out.

Hi. I am Agender and I feel better telling my friends online to call me they/them but, I have been in the closet for about a year now and I still don't know how to come out. My mom is now straight even though she used to be lesbian and got divorced when i was really young so I don't see much of my other mom now. She now dates other men and doesn't seem very into the community as she was before. When she was in college she and my other mom started the first LGBTQ+ group in the city. I came out as Panromantic and Asexual about a year ago while keeping my discomfort about my gender a secret. My BFF recently came out to me as Trans and neither of us know how to come out about our identity. We both know that October 11th is Coming Out Day and I was planning on baking a cake with the Non-binary flag on it but honestly, I'm not even sure if my mom will know what it means and even though I have waited a year, I don't know if I could wait that long. I have given her hints as to not answering when she calls me young lady or anyone calling me Ma'am but she doesn't seem to understand why. I was wondering if any other people have stories about their coming out experience or tips on how to come out as either Trans or Agender. 

Thanks,
      NonBiPie