Nothing much. Just rotate the tires, check the pressure, and check the fluid levels. I took mine in just to establish a service history of a responsible owner.
I had them do an oil change at 5000K. It was free, but comes off of the total changes, so I'll eventually end up paying.
You could ask that the backup beeper be set for just one beep instead of multiple beeps. That is, unless you like the beeps! The dealer makes this adjustment if you prefer it.
Don't you have Toyota Care? They should have a schedule for you. I'm sure the service people will provide it for you if you ask them. I think oil change 10k miles.
I passed on the 5000 mile check for personal convenience. I can check fluid levels and rotate tires. Anything else can wait another four thousand miles.