Once he wakes up, Ethan will want a few things before you can go downstairs (this is essentially a tutorial that explains some of the basics of the game). 

1) After completing those few steps, you will want to go downstairs and locate your office (near the kitchen). Sit down at the Drafting table and follow the prompts to work on the drawing. Keep pressing the indicated action until Ethan signs his name and the prompts no longer appear.

2) When your family arrives, you will need to help carry in the groceries and are asked to set the table. Walk over to the cabinet next to the table and follow the prompts to take out the plates and set the table.

3) Go outside and play with the kids...
..........a. You will need to win the sword fight
..........b. Don't stop the shoulder ride until prompted to do so

The trophy will pop up during the loading screen after The Prologue. You will also get the "Interactive Drama" trophy as well.