Espero alcanzar un nivel en el que pueda leer novelas sin diccionario.

Because the subject is the same for both actions: I hope, and I reach the level.

In Spanish, when the same person does both actions, you usually use:

• esperar + infinitive

So:

• Espero alcanzar... = I hope to reach...

If the subject changes, then Spanish normally uses que + subjunctive:

• Espero que alcances un buen nivel. = I hope that you reach a good level.

So espero alcanzar is the natural choice here.

Here, alcanzar means to reach, to attain, or to achieve.

So alcanzar un nivel means:

• to reach a level
• to attain a level

It is a very common verb in this kind of context:

• alcanzar una meta = to reach a goal
• alcanzar un nivel avanzado = to reach an advanced level

In this sentence, it sounds natural and fairly standard.

Because the sentence is talking about some level, not a specific one already identified.

• un nivel = a level
• el nivel = the level

The speaker is not referring to one previously mentioned level, but to an as-yet unspecified level of ability.

So:

• Espero alcanzar un nivel... = I hope to reach a level...

If you said el nivel, it would suggest a specific level already known from context.

En el que means something like at which, in which, or more naturally here, where.

The noun before it is nivel, and the clause explains that level:

• un nivel en el que pueda leer novelas...
• a level at which I can/may be able to read novels...

Spanish often uses a preposition + relative pronoun structure:

• la casa en la que vivo = the house in which I live
• el momento en el que llegó = the moment when he arrived
• un nivel en el que... = a level at which...

It may feel more formal or more structured than English, but it is very normal Spanish.

Yes, many speakers would understand and even say:

• Espero alcanzar un nivel donde pueda leer novelas sin diccionario.

However, with nivel, many teachers and careful writers prefer en el que, because donde is most literally associated with places.

So:

• en el que = more precise / often preferred in formal or careful Spanish
• donde = common and understandable, especially in everyday speech

For a learner, en el que is a very safe choice.

Because Spanish uses the subjunctive after expressions like this when you are talking about a hoped-for or not-yet-real situation.

The sentence is not describing a current reality. The speaker is hoping to reach a level such that they will be able to read novels without a dictionary. That level has not necessarily been reached yet.

So Spanish says:

• Espero alcanzar un nivel en el que pueda...

not normally:

• ...en el que puedo...

Why subjunctive here?

Because the clause describes a non-specific, desired, future, or hypothetical level. This is a very common pattern:

• Busco un libro que sea fácil de leer.
• Quiero una casa que tenga jardín.
• Espero llegar a un punto en el que pueda entender todo.

The subjunctive signals that the thing is not presented as an existing, definite reality.

Not in this structure.

Spanish normally does not use the future tense after en el que in this kind of relative clause. Instead, it uses the subjunctive:

• Espero alcanzar un nivel en el que pueda leer novelas...

This is the idiomatic Spanish pattern.

If you want to use the future idea more directly, you would usually restructure the sentence, for example:

• Espero alcanzar un nivel y entonces podré leer novelas sin diccionario.

That means:

• I hope to reach a level, and then I’ll be able to read novels without a dictionary.

So podré is possible in Spanish, but not naturally in the original sentence structure.

Because after sin, Spanish often omits the article when speaking generally.

So:

• sin diccionario = without a dictionary
• sin coche = without a car
• sin problema = without a problem
• sin ayuda = without help

This sounds general and natural.

If you say sin un diccionario, it can sound more specific, as if you mean without a particular dictionary or you want to emphasize the countable object more strongly. In this sentence, the general idea is intended, so sin diccionario is best.

Because the sentence means reading novels in general, not specific novels.

• leer novelas = to read novels / novels in general
• leer las novelas = to read the novels / some specific novels already known

Spanish often leaves out the article when talking about plural nouns in a general sense after a verb:

• Me gusta leer libros. = I like reading books.
• Quiero comprar flores. = I want to buy flowers.
• Puedo leer novelas sin diccionario. = I can read novels without a dictionary.

So novelas without an article is completely normal here.

It specifically means novels.

• novela = novel
• libro = book

So if you want the broader idea of books, you would say:

• leer libros sin diccionario

But novelas is more specific and probably suggests a higher reading level, since novels are often more demanding than simpler texts.

The given word order is very natural:

• Espero alcanzar un nivel en el que pueda leer novelas sin diccionario.

You can sometimes rephrase it, but not all changes sound equally natural.

For example, this is also possible:

• Espero llegar a un nivel en el que pueda leer novelas sin diccionario.

That uses llegar a instead of alcanzar.

You could also say:

• Espero alcanzar un nivel donde pueda leer novelas sin diccionario.

But if you move things around too much, the sentence may sound awkward or overly marked. For a learner, the original order is an excellent model.

Both can work here, and both can mean to reach.

• alcanzar un nivel
• llegar a un nivel

The difference is mostly one of style and collocation:

• alcanzar can sound a little more like attain/achieve
• llegar a can sound a little more like get to/reach

Both are common, but alcanzar un nivel is very natural in discussions of language progress, skills, and goals.

Because nivel is simply a masculine noun in Spanish:

• el nivel
• un nivel

There is no special grammar reason that will help you predict it from meaning alone; it is just something to learn with the word.

A useful habit is to learn nouns with their article:

• el nivel
• la novela
• el diccionario

That makes agreement much easier later:

• un nivel alto
• una novela larga
• un diccionario bueno

Yes. It sounds natural and correct in Spanish from Spain.

It is slightly on the careful, standard side rather than super casual, but it is absolutely normal. A native speaker might also say similar alternatives such as:

• Espero llegar a un nivel en el que pueda leer novelas sin diccionario.
• Espero llegar a tener un nivel con el que pueda leer novelas sin diccionario.

But your original sentence is clear, idiomatic, and well formed.