When you Are try to see if a variable is equal to another
you need to use "=="
here is correct version
if (BoxerSelectScript.challengerBoxer == playerOne):
also one more thing, you will get another error if you do not put ":" after each IF statements
if you did exactly it would look like this (copy and paste)
var currentfighterOne = BoxerSelectionManager.fighterOne.instance()
Globals.fighterOne.set_name(str(get_tree().get_network_unique_id()))
Globals.fighterOne.set_network_master(get_tree().get_network_unique_id())
Globals.fighterOne.position.global_transform = Vector3(1.391, 0.718, -1.482
if (BoxerSelectScript.challengerBoxer == playerOne):
Globals.fighterOne.set_script(FighterSelectionManager.playerScript)
if (BoxerSelectScript.fighterOne == playerTwo):
Globals.fighterOne.set_script(FighterSelectionManager.playerScript)
if (BoxerSelectScript.fighterOne == null):
Globals.fighterOne.set_script(FighterSelectionManager.AIScript)
add_child(Globals.fighterOne)