What was the significance of Aaron’s staff in the ark?

Numbers 17:

The LORD spoke to Moses, saying, 'Speak to the people of Israel, and get from them staffs, one for each fathers' house, from all their chiefs according to their fathers' houses, twelve staffs. Write each man's name on his staff, and write Aaron's name on the staff of Levi... And the staff of Aaron was among their staffs... On the next day Moses went into the tent of the testimony, and behold, the staff of Aaron for the house of Levi had sprouted and put forth buds and produced blossoms, and bore ripe almonds.'

Click to expand...

Aaron's staff was significant primarily because it validated the Aaronic priesthood through a miraculous sign. After a serious challenge to Aaron's authority (Korah's rebellion), God commanded each tribe to submit a staff. Only Aaron's staff miraculously budded, blossomed, and produced almonds overnight, demonstrating God's choice of Aaron and his descendants for the priesthood.

Hebrews 9:

4 Having the golden altar of incense and the ark of the covenant covered on all sides with gold, in which was a golden urn holding the manna, and Aaron's staff that budded, and the tablets of the covenant."

Click to expand...

The three items in the Ark each symbolized different aspects of God's relationship with Israel:

1. Tablets - God's Law and moral authority
2. Manna - God's provision and faithfulness
3. Aaron's Staff - God's chosen leadership and priesthood

Was Aaron’s staff the same one Moses used to part the Red Sea? If so then I totally get it! Or did Aaron have his own?

No, they were actually two different staffs. Moses' staff was famous for the miraculous signs in Egypt and the parting of the Red Sea. Aaron had his own staff, which budded and was later placed in the ark. It represented God's establishment of the priesthood, while Moses' staff represented leadership and deliverance.