Я особо не волнуюсь.

In this sentence, особо means something like particularly, especially, or all that much.

So:

• Я не волнуюсь = I’m not worried / I’m not worrying
• Я особо не волнуюсь = I’m not particularly worried / I’m not too worried

It softens the statement. The speaker is not saying I have zero concern at all, but rather I’m not very concerned.

Не is the normal Russian word for not.

• волнуюсь = I worry / I’m worried
• не волнуюсь = I don’t worry / I’m not worried

In Russian, не usually goes directly before the word it negates, and here it negates the verb.

That ending shows two things at once:

1. it is 1st person singular: I
2. the verb is reflexive

The full dictionary form is волноваться.

This verb conjugates like this:

• я волнуюсь = I worry / I’m worried
• ты волнуешься
• он/она волнуется
• мы волнуемся
• вы волнуетесь
• они волнуются

So -юсь is just the I-form of a reflexive verb ending in -ся.

A reflexive verb in Russian usually ends in -ся or -сь.

With волноваться, the reflexive form has developed its own meaning: to worry, to be nervous, to get anxious.

You do not need to translate the reflexive ending literally here. It is not really I worry myself in natural English. Just learn волноваться as the normal verb for to worry / be nervous.

Compare:

• волновать = to disturb, to worry someone
  
  • Это меня волнует. = That worries me.
• волноваться = to worry, be worried
  
  • Я волнуюсь. = I’m worried.

Yes, я can often be omitted in Russian, because the verb ending already shows who the subject is.

• Я особо не волнуюсь.
• Особо не волнуюсь.

Both are natural.

Including я can make the sentence a little clearer, slightly more personal, or a bit more contrastive depending on context. But in everyday speech, dropping it is very common.

Yes, they are very close in meaning, and both are natural.

• Я особо не волнуюсь.
• Я не особо волнуюсь.

Both mean roughly I’m not particularly worried.

A small nuance:

• не особо is very common in colloquial speech and often feels a bit more conversational.
• особо не is also common and sounds perfectly natural.

In most everyday situations, you can treat them as near equivalents.

It can mean either, depending on context.

Russian present tense often covers both:

• a general state/habit: I worry
• a current feeling: I’m worried

So Я особо не волнуюсь could mean:

• I’m not particularly worried
  or
• I don’t really worry much about it

Usually the context tells you which is more natural in English.

Both can mean I worry, but they are not always identical.

• волноваться often suggests being nervous, emotionally agitated, or anxious
• беспокоиться often suggests being concerned or uneasy about something

Examples:

• Я волнуюсь перед экзаменом. = I’m nervous before the exam.
• Я беспокоюсь о сыне. = I’m worried about my son.

In your sentence, Я особо не волнуюсь sounds like I’m not too worried / I’m not really nervous about it.

Because Russian does not always need to state the object of worry if it is already understood from context.

English often says:

• I’m not too worried about it

Russian can simply say:

• Я особо не волнуюсь.

If you want to add about something, you can:

• Я особо не волнуюсь из-за этого. = I’m not particularly worried about this / about it.
• Я особо не волнуюсь по этому поводу. = I’m not particularly worried about it / about that matter.

The usual stress is:

• Я
• осо́бо
• не
• волну́юсь

So the stressed syllables are:

• осо́бо
• волну́юсь

That gives you: ya a-SO-ba nye val-NU-yus'

A rough English-style approximation is:

val-NU-yus'

A bit more carefully:

• во sounds closer to va
• лну is a consonant cluster, so say it smoothly: val-NU...
• юсь is like yus’, with a soft final consonant

The whole sentence sounds roughly like:

ya a-SO-ba nye val-NU-yus'

Not perfect English spelling, of course, but it can help as a first step.

Yes. Russian word order is flexible, and changing it can shift emphasis.

Neutral order:

• Я особо не волнуюсь.

Other possible orders:

• Особо я не волнуюсь.
• Не особо я волнуюсь.
• Я не особо волнуюсь.

These all mean roughly the same thing, but the emphasis changes a little.

For a learner, Я особо не волнуюсь and Я не особо волнуюсь are the safest and most natural patterns to use.

It is neutral-colloquial and very natural in everyday speech.

• Я особо не волнуюсь sounds normal in conversation.
• It is not slang.
• It is not highly formal either.

In a formal context, a person might choose something slightly more formal such as:

• Я не испытываю особого беспокойства. = I am not particularly concerned.

But in ordinary spoken Russian, Я особо не волнуюсь is completely natural.