Transfer from Beijing Capital Airport Terminal 3 to Terminal 2 - 144 Hrs Visa needed?

Hi,
I am arriving at 5.15 AM with Swiss LX 196 at Terminal 3 and have a Flight at 8.10 AM with China Southern from Terminal 2 to Seoul. I only travel with hand baggage. Do I have to make a 144 hours Visa if I have to get the boarding card? Or can i get the boarding card at a transfer desk? Do i have enough time? Thank you for your help!!