Hi there, thanks for trying the game! Feel free to download the newest version of the game—there are a few edits that may help clarify things.
You draw from your personal deck, and discard to your personal discard pile. When you acclimate from the center, the card you select also goes to your personal discard. Whenever you need to draw and are out of cards in your personal deck, you shuffle your personal discard pile and flip it over—it's now your deck!
So you start with three cards (2,4,7) in your deck. The first turn you play those three cards and then they go into your personal discard pile along with any cards you acclimated to in the first turn. Then, at the end of your turn, you draw three cards. You have no cards left to draw, and so you shuffle your personal discard pile, flip it over, and draw three cards. Over time you will grow your deck, but you continue to cycle through your personal deck/discard pile as you acclimate.
Let me know if you have further questions. Hope you enjoy!