Después de clase quiero pasar por la librería para buscar una novela fácil en español.

Después de clase means after class.

There is no article here because Spanish often leaves out the article in set expressions like this when speaking generally:

• después de clase = after class
• antes de clase = before class
• en clase = in class

If you say después de la clase, it usually sounds more like you mean after the specific class/session.

So:

• Después de clase = after class, in general
• Después de la clase = after the class, a particular one

Both are possible, but they are not exactly the same.

• ir a la librería = to go to the bookshop
• pasar por la librería = to stop by the bookshop / to drop by the bookshop

Pasar por suggests a quick or convenient stop, often as part of your day. In this sentence, it gives the idea:

After class, I want to stop by the bookshop...

That sounds very natural in Spanish.

No. This is a very common false friend.

In Spain:

• librería = bookshop / bookstore
• biblioteca = library

So pasar por la librería means to stop by the bookshop, not the library.

Here, pasar por means to go by, to stop by, or to drop in at a place.

It does not literally mean pass through in this sentence. The idea is that the speaker intends to make a brief visit to the bookshop.

Examples:

• Voy a pasar por tu casa. = I’m going to stop by your house.
• Pasé por la farmacia. = I stopped by the chemist’s/pharmacy.

Para introduces the purpose of the action.

So:

• Quiero pasar por la librería = I want to stop by the bookshop
• para buscar una novela fácil en español = in order to look for an easy novel in Spanish

Together, it means the stop has a purpose.

In English, we often just say to:

• I want to stop by the bookshop to look for...

In Spanish, para + infinitive is very common for this idea of purpose.

Because buscar means to look for, while encontrar means to find.

The sentence expresses the speaker’s intention to search, not the result.

• buscar una novela = to look for a novel
• encontrar una novela = to find a novel

So para buscar una novela fácil means the person wants to go and see if they can find one, not that they already know they will.

In Spanish, adjectives usually come after the noun.

So:

• una novela fácil = an easy novel

That is the normal word order.

If you put many adjectives before the noun in Spanish, it can sound literary, emphatic, or change the nuance. For a basic descriptive adjective like fácil, the usual place is after the noun.

Here, en español describes novela.

So the meaning is:

an easy novel in Spanish

Not:

• searching in Spanish
• going to the shop in Spanish

The structure is understood as:

• buscar [una novela fácil en español]

So the novel is:

1. a novel
2. easy
3. in Spanish

Yes. That is a very natural alternative.

• una novela fácil = an easy novel
• una novela fácil de leer = a novel that is easy to read

The second version is more explicit and may sound more natural in some contexts, especially if you want to stress reading difficulty.

For a learner of Spanish, both are understandable and useful.

Because Spanish often uses the present tense to express a current intention or desire.

• quiero pasar por la librería = I want to stop by the bookshop

The wanting is happening now, even if the visit will happen later.

This is just like English:

• I want to stop by the bookstore after class.

If you wanted to focus more directly on the future plan, you could also say:

• Después de clase voy a pasar por la librería...

But quiero is perfectly natural if the speaker is expressing what they want to do.

Yes. In this sentence, clase usually means class in the sense of a school or course session.

Depending on context, it could refer to:

• one class period
• a lesson
• a session of a course

So Después de clase is a very natural everyday way to say after class.

It depends on the variety of Spanish.

In Spain, Después de clase is the most natural choice in a sentence like this.

In some Latin American varieties, después de clases can also be common when referring more broadly to school/classes.

Since you are focusing on Spanish from Spain, Después de clase is the best version to learn here.

The original sentence is already natural, but here are a few very natural Spain-style alternatives depending on nuance:

• Después de clase quiero pasar por la librería para buscar una novela fácil en español.
• Después de clase quiero pasar por la librería a buscar una novela fácil en español.
• Después de clase quiero pasar por la librería para ver si encuentro una novela fácil en español.

Nuance:

• para buscar = to look for
• a buscar = also common after a movement idea, a bit more direct
• para ver si encuentro = to see if I can find

That last version is especially natural in everyday speech.