Hi Lonely and welcome to the Forum.
The UN has been a conversation starter for sure. I started one like this "Did you know that we were members of the UN? crazy huh" but my suggestion would be to let it happen as natural as possible. When an oppurtunity arrises and you feel confident ease into it. If you get marked as an independant thinker with a dangerous mind, you may only get that one shot. So take is as slow as you feel the need to.
Slowly revealing a little Watchtower past gets some to thinking too. I know I was shocked to learn that Bethel used to celebrate Christmas and so many changes have taken place. No need to win any arguments until you are ready to be marked or disfellowshipped, that is a big step.
Continue in your research and learning for personal growth and you will see doors open up to share what you discover. Love~Kate; apostate from the WTBTS, never from God.