NASA does plan to go to an asteroid, grab a big bolder, and put it in orbit around the moon. After that they want to send astronauts there to explore it and bring back samples to Earth.
As far as actually doing commercial mining on one of these things is pretty far off into the future. We’d have to know there was something so valuable there that it was worth the time and expense. Right now we know nothing, and retrieving a few small samples from one of them is going to cost about a billion dollars.