How do you learn the Spanish/Ruy Lopez?

Find an old book named "Mastering the Spanish" by GM Danny King and NM Pietro Ponzetto.

It does not cover all the plans and structures, but it is a very good read- as well as an easy one.

And you may have understood already that if you try to learn how to play a certain position by consulting an engine, you are out of luck. Engines are useful to advanced players who are already familiar with the plans, and need to refine executional details and particular move orders.

Spanish is king of openings one doesnt master it just like that.

I think they should. It's the first opening recommended by experienced players (alongide the Queen's Gambit) for a reason.

Since you have a chess.com account here, maybe start with the opening chess lessons for the Ruy Lopez. Probably start off light, and see (but know memorize any moves) what the variations are on the Ruy Lopez Wikipedia page.

best way is to look at grandmaster games in that opening. there is a lot of theory but the ideas are pretty straightforward

Mastering the Spanish as recommended by pfren is available online to borrow from archive dot org. Use the search to find it, mediatype is texts.

Su

I doubt you can get it on e-book

The Ruy Lopez has a huge theoretical base. In addition, the various subvariations (Open, Berlin, Exchange, Morphy, Steinitz. Schliemann, etc.) have quite distinct features. So, setting out to “learn” the Ruy is very ambitious.

My advice is to take it slow and easy. Start with one variation. Do not try to memorize sequence after sequence. Focus instead on the major ideas. A good writer will try to identify a few themes that run across multiple lines. It is easier to remember these themes than it is to memorize sequences of moves.

Then, look at 5 to 10 Grandmaster games in the line. Try to find annotated games that explain the developing plans. Later, you may find it easier to remember these plans and the general ways that the player won than the exact sequences of moves.

Continue with the same subvariation for a week or so. By then, you will have seen some 25 to 50 games in the line. You should try to apply the themes mentioned by the writer. You may also be able to see some themes of your own.

move on to a different variation the second week. And repeat.

If you want to combine play with study, see if you can steer a few speed games into the line you are studying. But don’t binge play. The focus should be on applying what you are learning.

with an opening as complex as the Ruy, don’t try to learn everything at once. Trying to do that will fail and will be more frustrating than helpful.