I want to connect lo-voltage track lighting to the wiring in an existing wall outlet. Can I do that? Is there enough "power" in that wall outlet circuit to handle the track heads?
Connecting low voltage lighting to high voltage supply requires a step-down transformer or power supply unit of some kind. You cannot connect high voltage directly to low voltage lighting; voltage doesn't magically step down that way; it is illegal because it'll cause a fire.
There should be plenty of power.
Your hookup issue is mostly mechanical. You might use a "wall wart" transformer/power supply that simply plugs into one of the outlets. Or you could hard-wire it using surface conduit and a spacer that extends the outlet so you make your connection underneath it.