After entering the game, you will see the day count and your stats on the right top corner, you will see the day count go up, and the game ends on day 7. Also pay special attention on your stats, because you will lose if any of your stats reaches zero!

To start the game, you need to choose between a few stereotypical character perk. Each gives you different effect on your stats, it will show on your screen like this:

After starting the game, you need to click the button under the question to place your choice.

Anyway, that is all you need to know, good luck!