After I install my ball valve on the threaded mash tun it is upside down. What should I do?

When you add about 5 wraps of tape, you should be able to rotate it into the correct position with the handle UP.

If that doesn't work for you after you tighten it up you can always remove the 4 nuts on the valve and reorient the valve in 90-degree increments.

It's pretty easy to take the valve apart, even when mounted and we assume you already did that when you were doing your pre-cleaning work.