It's hotter than a whore house on nickel night
Attic insul is biggest bang for buck. Over insulating is always worthwhile. If you ever have the walls open for a project, improve the insulation. It doesn’t wear out. It’s cheap comparatively to other building systems.
If your windows are old, then those may offer bigger energy improvements, but that is invariably spendy.
A/C is a net loss for $ & energy, but comfort is significant even in a moderately insulated space.
IF AT ALL POSSIBLE, insulate the full shell of the house & keep the mechanical systems INSIDE the thermal envelope..ie no vented crawl space or vented attic. This works in all climates, but is especially noticeable in the ones with bigger thermal swings. Only downsides: not super cheap & not as easy to do in a remodel situation.
Attic fan not really worth much. I’d change the color of my roof shingles first & I like them dark.