A comfortable pack that fits what you need for a few days and that you can actually carry.
Look for
About 30-45 liters for one adult
Padded shoulder straps and a hip belt
Water-resistant fabric or a rain cover
Colors and style that suit how you will use it
Avoid
A pack so big it gets too heavy to carry
Tip
Pack it, then walk around the block with it. If it hurts, lighten the load.
This guide is general advice and will be checked by a preparedness reviewer before release. Partner reviews and store links will appear here later, always clearly labelled.