There is information regarding ground transportation scattered across the arrivals level of CDG as well as information kiosks. There's many options to get into the city including RER (express and commuter services), RoissyBus direct to Opéra and Les Cars Air France (AF shuttle service).

Also, I believe (not sure) LH flies out of T1 while AC flies out of T2 so it'll involve a journey on the CDGVAL in order to get to the concierge office anyway.

The 3 services are comparable in terms of time/price, but the best choice really depends on where you are specifically trying to go.