>>362186920
Cats tool doesn't have an AO bake option as far as I know. You can use a program like Substance Painter or a free alternative like https://armorpaint.org/, Blender isn't the best for texture painting.
or if you just want to know how to do AO in blender:
https://www.youtube.com/watch?v=Zum2jlruecw
skip the step where you make a new UV map.