There is a sign in front of the YC Tent but if you didn't know where it is, it could be confusing. It's easier for me to explain first where you go to get escorted into the terminal. That's to the far left (the opposite side that you drive in). Now if you continue on the road which goes left, it will be past the taxi drop off/ pick up area. At this point, you should see the blue tent. Hopefully that makes sense. After you drop your bags off, just go to the terminal and you'll see the roped off area for YC guests (left side of the terminal). Someone will be there with a list of YC guests.