Building on what Aarin said, this website has a lot of good Do's and Don'ts for being better allies to trans people: https://uwm.edu/lgbtrc/support/allies/trans-ally-tips/
And here's some tips on creating gender neutral bathroom spaces: https://www.uua.org/lgbtq/welcoming/ways/bathrooms
-If you're doing a gender neutral bathroom, use signage that reflects nonbinary identities. For example, the "male/female" bathroom signs for single-stall restrooms aren't inclusive of nonbinary identities. Choose language like "All genders welcome". In general, avoid saying "the two genders" or "both genders" because the existence of nonbinary people proves that there are more than two genders :)
-Also regarding pronouns, when you mess up someone's pronouns (and you WILL! Most of my friends are trans and I still mess up sometimes if I'm tired or if it's someone I recently met), just correct yourself and move on. Don't make it a big thing - it's really not about you and making it a big deal just makes us feel like our presence is inconvenient for you. If you don't know someone's pronouns, ASK THEM. If you're cisgender (i.e. not trans) and folks are doing pronoun introductions, please just share your pronouns. Definitely don't make a joke about it or say something like "You can call me whatever you want." - doing that is guaranteed to get you some eyerolls and lack of trust from trans people in the room. PLEASE just share your pronouns (most likely he/him or she/her) and move on.
I also do want to note that, while cisgender people shouldn't assume it is a trans person's role to educate them on gender identity issues, I recognize that there are a LOT of misinformed and even downright hateful "resources" on the internet, so I do set myself up to do some education in this area. So if you've got questions, I'll answer them as I have the energy and capacity.