Cylinder head question....
The heads can go on either side, no issues there.
The pushrods are all the same, no issues there.
NOW, when you install the rockers/shafts look at one end of the shaft, there will be a notch on one end.
The notch must be toward the front and down on the driver side.
The notch must be toward the rear and down on the passenger side.
If you don't get that part right you will have oiling problems.
Head gaskets "might" confuse you, it will appear that one is upside down, that's normal, as they are both the same. Just line them up with the dowels.
When you pulled the shafts/arms did you do so as a unit? It is easier that way. There is a specific way they go on the shaft so they line up.
AND BTW the only dumb question, is the one not asked!