Triad or Throupple Relationship Advice?

Elle

My straight cis male fiancé and I (bisexual female) have been dating a woman together for a month or so and honestly we are having a great time getting to know her and I definitely have fallen for her. Anyone here been in a poly relationship and have good advice for us? Even three some advice. I haven’t been in a three some in YEARS I am super nervous but eventually when we get to that point I don’t want to look like an idiot. Let me know! We both see and want a long term relationship with her and are invested. So please no negative comments needed, we know what we are getting ourselves into.