I have a feeling wasn't paying close enough attention if the game explained it, but now the Armor is out of power and I have no clue what to do...

What you need is another Fusion Core.
I have not seen many places in the game where those occur either, so far.

The console is an option on a PC, but using it depends on your play style.

There is places around the map that have power armor with fusion cores still in them, you can buy them from vendors. And I opened a box earlier and there was 4 in it.

I'm on Xbox One...

OK cool I'll just have to keep an open eye. Thanks

In the inventory menu, where would the fusion core be located?

No problem, good luck!

there is a cap exploit if you want to get around that just use it and buy out the FCs

iv got over 30 FCs. Keep finding them in major structures

It's under Ammo. Also, be aware that there is a difference between Fusion Cells (Energy Weapon Ammo) and Fusion Cores (Power Armor battery).

Thanks everyone!