My company is too small for an LGBT ERG. Instead I created a private slack group called Committee Rainbow and invited all the queer folks in my office to join. We've been using it for a couple months now to share queer memes and jokes with people we know will understand. It's not quite ERG level of support, but it's nice to get all of the LGBTQ+ people in company talking in one spot.
It's also allowed me to get to know more of queer people in the office and find new people that I didn't realize were a part of our community! If your company doesn't have an ERG, I would recommend creating your own group however you can!