Where can I find the aerofoil geometry of a commercial aircraft so as to design it in CAD software?
All the current manufacturers develop proprietary airfoils combined with wing planform, washout, etc. using CFD for optimum pressure distribution, low drag, high critical Mach number, high maximum CL, benign stall propagation and benign aeroelastic characteristics. That applies to Boeing, Bombardier, Embraer and Airbus.
This type of info is not normally released by the manufacturers.
TCDS's do not have this kind of data.
You can do your own research starting with a standard NACA airfoils like those found in NACA report 640(Summary of Airfoil Data) and modifying them.