It won't let me switch to landscape mode when I turn my iphone?

I read that it must be locked into normal. It said I need to double click the home button and scroll all the way to the left and there will be a lock button to press. But I scrolled all the way to the left and right and it all just my apps! Is there a place in the settings I can go to unlock it instead?

You simply have your phone orientation locked to portrait mode. Swipe UP from the homescreen from the very bottom of the screen. This will bring up Control Center… Then press the top right icon.