I have it so other party member are walking around and when you talk to them, you can check their stats. Problem is I don't know how to show the stats of that specific actor you have talked to. I feel like it's really obvious, but can someone help?

I imagine it would be quite complicated, involving scripts and creating new windows just to display the actors' stats.
Like a custom stat window of sorts.

Unless the normal "display text" can also be used to get variables from $game_party or whatever the object that stores actor information.

Would something like this setup work for you, cll?