Hidden materia (spoilers)

[~Sound Sage~]

So I got up to the shinra building near the end of the game on my first playthrough on my ps4.

I noticed some materia in places i could see, but not get to.

How do i get the golden (yellow) materia in aeriths church? and how do i get to the materias locked behind the golden and red gates?

right now on the steam version I'm right after we get the blasting agent from the shinra base where the team visits jesses home.

are there any hidden materia around this part of the game i need to get?

[Shock_&_Awe]

I would look up a guide for the simplest solutions.
-For the gold materia (Chakra) in the church, once you start doing side quests with Aerith you can return to the church and get it.
-For the gold and red gates, there is a side quest in Chapter 14 where you will find and unlock those gates.

[The Costas]

When you beat the game you can go back to previous chapters to get stuff you couldnt reach before.