Writing Marginalized Groups

The first draft of my latest attempt at a novel has (among others) the following characters:

• A black school shooting survivor
• A sikh young man
• A transgender young man
• A person with Tourtette’s Syndrome
• A domestic violence survivor
• A hispanic woman with a PhD
• A lesbian
• A gay man
• A black man in the military

And many other characters with smaller rolls but who also represent minority or marginalized groups.

The main POV character is a white woman with a Christian upbringing. Her point of view I have down as a white woman. In writing the other characters, I did a lot of reading about these specific circumstances, cultures, and conditions both from an academic standpoint and, when possible, an own-voices standpoint. And, of course, I did not grow up in a bubble and have met or have friendships/relationships with people in each of these groups.

I tried my best to represent them fairly, accurately, and with sensitivity. I think I did okay, but I’m sure there is still plenty to learn and a lot for me to understand.

Here’s my question for you, writer hivemind on WordPress:

Who should I talk to, what should I read, or how should I go about utilizing resources to increase my personal knowledge, make my characters more complete and vibrant, and most importantly, appropriately represent the groups represented here?

I welcome any and all advice, truly!