I haven’t been able to beat any of the 2D Zeldas. I suppose that’s because the 3D Zeldas are a lot more linear, so I can just breeze through them without having to think too much.
I played the 2D Zeldas when they were newly published. Back then, Nintendo Power magazine was a thing people used to have. So strategy guides and hints and stuff weren’t hard to come by. Plus, I’d been known to call the Nintendo Power Hotline now and then. I still remember the phone number.
It’s not cheating to use a walkthrough or guide for a game—especially a nonlinear one, or if you intend to 100% it.