CTU has no place to exchange foreign currency in the domestic terminal. None. You would have to walk or take the shuttle bus to the international terminal which is 1 km away and I am sure it will not be open at 10 pm when the OP lands. If you arrive on a domestic flight without local currency exit baggage claim and head to the left. You will find some ATMs there and they have English as an option. As moondog said ATMs will be cheaper than using an airport foreign exchange counter anyway.

There is a large taxi ramp in the middle of the domestic terminal. Just head outside and go to the middle. The signage inside the terminal is not exactly precise because it has not been updated since they closed off half of the exits for security reasons. Just find an exit that is open, head outside to the sidewalk are and walk to the middle, you will find the taxis.

You can take public transportation to the Panda Research Center but it will require substantially more time than taxis. The tradeoff between time and cost is really up to you, depends on what else you want to do.