Having skegs, the 500 is not especially sensitive to mast rake, so the basic setting will be fine

Toe the rudders in by 5mm and tuck them right under

Set the spinnaker up like any f18

If the boat is going to be used as an intro to cats for a lot of people, you are right to try and get it set up properly. Get a cat sailor to take it for spin to make sure it feels right