Amy, you get to choose exactly which topics you want to talk about and which you don't.
No reason you have to say a word about your past or your relationship with your ex. Just say, "That's a long story and not one for today".
Then change the subject. Say "tell me what you like to do when you're not working" or anything.
There is an implied rhythm to conversation. Person 1 says something, and Person 2 responds, then asks a question of Person 1, and on and on. Like a tennis ball back and forth across the net.
You never have to answer a question you don't want to answer. Just give some pleasant and non-commital response, and move the conversation on with a question to a place you feel comfortable.
I understand where you are coming from. I've sometimes laughed to myself if a new guy in my life, when I'm ready, asks me about my past and my family, I could hardly answer on a first date "Well, my ex husband was an abusive porn addicted gambling alcoholic who I had to run away from, my mother was psychotic, my father was an alcoholic as was my brother and my brother tried to steal my inheritance from my aunt".
But that's the truth of what happened. It isn't the truth of who I am or who I am moving toward being.
Think new friend, here, on this picnic. Don't think "obligation to share every last horrible thing that happened to me." Think of the easy stuff that you might have in common - - do you like funny movies? What kind of restaurants do you like to go to? Are you a couch potato or into exercise?
We who have grown up in highly intense emotionally dramatic family structures think that is normal and expected from us. It isn't. You get to figure out how to just relax and have fun.
And if this really doesn't feel right, maybe it is too soon, and that is fine, too. Your voice on this forum is so much clearer and happier, and you have made astonishing progress and growth. So take it in your own time, nothing you don't feel comfortable with. You don't ever have to choose to be uncomfortable again.
ShootingStar1