If you’re out of all-purpose and your kitchen looks like a flour crime scene, just use bread flour and accept the slightly chewier result. Seriously, 90% of people won’t notice, especially if you’re making cookies or brownies.
Or use cake flour and enjoy the most delicate, crumbly shortbread known to humankind. The rule is: bread flour makes it chewy, cake flour makes it tender. Both are delicious; neither will end your baking career.
And if you’re really in a pinch? Just stare at the recipe, sigh dramatically, and order takeout. We’ve all been there, and pizza is basically bread, which is basically flour. You’re welcome.