FreeGameDev

So on my map, it's hard to describe but the textures are only appearing one-sided. Like they're only visible when they're facing away from the camera. Help?

That's normal, it's not an issue with the texture.
Each face has a 'normal' which decides which side shows up in-game. In Blender, you can tell it to show normals, or even do Backface Culling to hide the backfaces like you described happens in-game. If you want it changed, select the face/faces and Flip Normals

If you want something to show both sides, you may want to duplicate the face/s (Shift+D) and flip its normal (click Alt+N, flip. You can set a hotkey if you want).

The reason this is standard behaviour in many games is because reduces the amount of unnecessary faces that the game needs to calculate and render (you will never need to see the inside of most objects), making performance much better in large maps.

That's what I was looking for, thank you so very much.