How far from castle is campground is it close enough for Uber ride or no

You meet at the visitor center pay for a tour and you wait for a boarding call, they shuttle you up on a nice bus with a tour guide of the estate.

Yes about 2 miles apart very easy

It's close, not close enough to walk, but honestly I'm not sure how many UBER drivers are out there. It's pretty far from a 'metropoilis'. You might ask the camp ground if they shuttle to the visitor center.