Me esfuerzo por hablar en español sin miedo.

Because the verb is esforzarse, a pronominal verb. In Spanish, this verb normally includes a reflexive pronoun:

• me esfuerzo = I make an effort / I try hard
• te esfuerzas = you make an effort
• se esfuerza = he/she makes an effort

So me is not really to myself in a literal English sense. It is just part of how this verb is used.

Here, esfuerzo is the first-person singular present form of the verb esforzarse:

• yo me esfuerzo = I make an effort / I try hard

This can be confusing because el esfuerzo is also a noun meaning effort. So:

• Me esfuerzo = I try hard
• El esfuerzo = the effort

Same form, different job in the sentence.

Because after por, when you are expressing purpose or the action you are trying to do, Spanish uses the infinitive:

• Me esfuerzo por hablar...

So the structure is:

• esforzarse por + infinitive

Examples:

• Me esfuerzo por estudiar más.
• Se esfuerza por llegar temprano.

You do not say me esfuerzo por hablo.

With esforzarse, the normal pattern is esforzarse por + infinitive or sometimes esforzarse en + noun/infinitive.

So:

• Me esfuerzo por hablar en español = I make an effort to speak in Spanish

Using para here would sound unnatural with esforzarse.

A helpful way to remember it:

• por goes naturally with esforzarse
• para is more often used for general purpose: Estudio para aprender

But with this specific verb, por is the usual choice.

Yes. That is grammatical and natural.

There is a slight nuance:

• intento hablar... = I try to speak...
• me esfuerzo por hablar... = I make a real effort to speak...

Me esfuerzo often sounds a bit stronger, as if you are consciously working at it.
Intento is more neutral and simple.

Both are possible, but they are not used in exactly the same way.

• hablar español = to speak Spanish
• hablar en español = to speak in Spanish

In this sentence, en español emphasizes the language being used at the moment. It can feel a bit like saying in Spanish in English.

So:

• Quiero hablar español = I want to speak Spanish
• Quiero hablar en español = I want to speak in Spanish

Both are natural. En español is especially common when contrasting with another language or focusing on the act of using Spanish.

Because Spanish often leaves out the article in expressions like this when talking about a general feeling or state.

• sin miedo = without fear / fearlessly

Using el would sound more specific, as if referring to a particular fear already mentioned.

Compare:

• Habla sin miedo. = Speak without fear.
• Habla sin el miedo que tenía antes. = Speak without the fear he/she had before.

So in your sentence, sin miedo is the natural general expression.

Not exactly, though they are related.

• sin miedo = without fear
• con confianza = confidently / with confidence

Someone can speak sin miedo simply because they are not afraid.
Speaking con confianza suggests more self-assurance.

So sin miedo focuses on the absence of fear, while con confianza focuses on positive confidence.

In standard Spain Spanish, z is pronounced like the th in think.

So esfuerzo sounds roughly like:

• es-FWER-tho

Very roughly broken down:

• es
• fuer = like fwer
• zo = tho in Spain Spanish

In much of Latin America, that z would sound like an s, so it would sound more like es-FWER-so.

The original sentence is natural:

• Me esfuerzo por hablar en español sin miedo.

But Spanish does allow some flexibility. For example:

• Me esfuerzo por hablar sin miedo en español.
• Sin miedo, me esfuerzo por hablar en español.

These are possible, but the original sounds the most neutral and smooth.

Why? Because sin miedo naturally modifies hablar, and placing it after en español sounds very normal in everyday Spanish.

Yes, it is natural and correct in Spain.

It sounds like something a learner might say when talking about personal progress or confidence:

• Me esfuerzo por hablar en español sin miedo.

A native speaker might also say:

• Intento hablar en español sin miedo.
• Procuro hablar en español sin miedo.
• Hago un esfuerzo por hablar en español sin miedo.

But your original sentence is absolutely good Spanish and works well in Spain.