The first Zelda has some quite obtuse and weirdly-translated moments, but here's a tip: Pick up the manual. It's available online. The moment you do that, you realize the game was very much meant to be played with the manual in mind, providing much context, along with starting tips and hints to get you on the right path.

Other than that, it's quite good. You're not gonna get smooth movement on par with more recent Zelda games, but much like Castlevania, your limited controls are a deliberate way to make the combat more strategic. Dungeon-exploring is a good time, albeit the music can drive you nuts after a while. I put up a music playlist about halfway through the game to ease things up.

Overall, a respectable first entry to the series, as long as you don't mind its simplicity.