Advice for first FFM

Hello all! I (25m) am finally having my dream come true and my fiancé (26f) and I are inviting another woman into the bedroom. This will be all of our first time and I’m just looking for general advice i.e. Best thing to do for the first meet up, positions, getting past any awkwardness etc. anyone with experience who can tell me what to expect would be greatly appreciated! I want us all to have fun so I’m doing my part to make sure It goes smoothly!