Thanks for trying the game out. I’ll gladly point you in the right direction. You have to click on the clue called “A guest” to reveal the clue’s description (at the top of the screen) and follow-up actions at the bottom of the screen (Action area).
Keep in mind, that you can get softlocked by discarding vital actions/clues or running out of energy. You have to decide what actions to take based on their names and case information.
To restart the game you can go back to menu and click “Play” in the menu.