I forgot where you can add pictures of the cast, I was going to add this to chapter one but decided to create a separate part specifically for the characters and actors.
Honestly everyone I've chosen is a little older than the age range I am picturing. The actor I like for Kurt kind of works for that age.
Tatyana: (sorry the picture is so huge) Carmela Zumbado, most recently from the TV show You.
Kurt: Jake Johnson, New Girl - I am currently going back through the New Girl phase and am obsessed. Also have been enjoying the new show he's in called Dex. (IDK when it's coming back though)
Callum: Alexander Ludwig, loved him when he was younger (Race to Witch Mountain) and then he was creepy in Hunger Games. He's also been in a lot recently. Also again GIANT picture whoops
Okay, that is it so far. I can't think of anyone that fits Adriana right now. But the three above are pretty close ideas of who I am picturing.