Two months ago my 95 Blazer blew the return hose on the power steering pump. The hose clamp failed. When it sprayed the fluid all over the engine etc. for some reason the transmission stopped functioning. When you put it into gear it may drive with no problem for 200 yards then quit. Reverse will allow you to back the car up almost to your starting point. Let the vehicle sit for 30 minutes and you can do it again. This is a rebuilt tranny with about 50,000 on it. The engine was also replaced with a crate motor about 70,000 miles ago. On top of all this there was 1,400 in repais done to the AC system. Thank goodness all of this was paid for by the original owner shortly before I bought it from him. My plan is to start with fluid and filter change and then move forward. If this doesn't help then I am seriously considering taking it to pull a part or selling it. Is there any type of sensor or switch under the hood or on the tranny that could have been blasted with the fluid and cause it to do this? Second question is there anything that might have pulled the fluid out of the tranny at the same time? When the wrecker brought it home there was almost zero fluid in the tranny. I know it was full because I had just completed the maintenance check when buying gas.

As you mentioned, the first place to start is servicing the transmission with a new filter, gasket, and use Dexron VI (6) fluid.
While you are under there, I would have some spray electronic contact cleaner handy and compressed air, & consider removing the transmission electrical connectors. Look for PS fluid residue/ inspection.
Did you power wash after the PS hose broke, where water could have into other connectors as well?
I dont know where all else that high pressure PS fluid is, but if it did get into connectors, cleaning may help.
Of course once the new fluid and connectors are checked & clean, it may be worthwhile to use a shop scanner and check for any history & stored codes.
It may point to some PCM codes that may be helpful.