Final answer:
Before leaving on his quest, Percy is given Athena's reflective shield and the winged sandals of Hermes.
Step-by-step explanation:
Before leaving on his quest, Percy is given two magic items: Athena's reflective shield and the winged sandals of Hermes.
The reflective shield allows Percy to cut off Medusa's head without directly looking at her by flying over her and looking only at her reflection.
The winged sandals of Hermes allow Percy to move quickly and fly, which is helpful during his adventures.