Make sure you have (and know where to locate!) the items on the Gear Checklist.
Camera or Phone Camera Camera battery & charger (or phone and charger) Lens (for a DSLR or mirrorless camera) with a lens cap Memory card or (for phones) storage space You can also gather optional gear if you desire.
Optional Gear Checklist:
Tripod Camera bag or phone case Lens cap/UV filter Cleaning kit Camera strap Polarizing filter