5) Deal cards: Players new to Terraforming Mars each get a Beginner Corporation card. The other players are dealt 2 normal corporations. All players then receive 10 project cards.
6) Choose cards: A Beginner Corporation gets to keep all their cards for free, while the other players now simultaneously choose which corporation to play, and what project cards to keep in their starting hand. (Each card you keep will cost 3 M€ from the corporation you choose.)
7) Starting conditions: In player order, each player reveals which corporation they will play, gets any starting resources and production stated on the corporation card, and pays for the cards they keep. Each card costs 3 M€, and the remaining cards are discarded in a common discard pile - cards are always discarded face down! Put the discarded corporation back in the box. Be aware that your resources for the following few generations will be quite limited until you get your economy going.
8) Start the game: The first generation starts without a player order phase and without a research phase (since you just performed those phases during setup), so the first player just starts the action phase.