Several years ago we stayed at a Passport Am. park called Pea Patch. It was just off the strip and we walked to a few shows. The theaters are scattered over a large area, so depending on what you want to see, this location might not work.
One attraction I would suggest you consider is the Titanic. We really enjoyed touring it - it does look quite tacky from the street, but is actually very well done. If I recall, it is right downtown.
There is another park that might work for you, but we have not stayed there and I am not sure of the name. It is right on the river and I think it would be an easy walk to the main drag. RV park reviews might have it listed.