Eu vou fazer a matrícula do meu filho na escola amanhã.

Yes, you usually can leave it out.

Portuguese often drops subject pronouns when the verb already makes the subject clear. So:

• Eu vou fazer a matrícula do meu filho na escola amanhã.
• Vou fazer a matrícula do meu filho na escola amanhã.

Both are natural.

Including eu can:

• add emphasis
• make the subject extra clear
• create contrast, like I’m the one doing it

So in normal conversation, dropping eu is very common.

Vou fazer is the very common near future structure in Portuguese:

• ir + infinitive
• vou fazer = I am going to do / I will do

It is extremely common in everyday Brazilian Portuguese.

You could also say:

• Farei a matrícula do meu filho na escola amanhã.

But that sounds more formal or written. In normal speech, vou fazer is much more natural.

Because in Portuguese, fazer a matrícula is a very common expression meaning to enroll someone / to do the registration/enrollment.

Literally:

• fazer = to do / to make
• a matrícula = the enrollment / registration

So together:

• fazer a matrícula do meu filho = enroll my son / do my son’s enrollment

Portuguese often uses a verb + noun expression where English uses one verb.

You may also hear:

• matricular meu filho na escola

That is also correct, but fazer a matrícula is extremely common and natural.

In this sentence, matrícula means school enrollment or registration.

In Brazilian Portuguese, matrícula is commonly used for:

• enrolling in a school
• registering for a course
• the act/process of officially signing someone up

Depending on context, it can also refer to:

• the enrollment itself
• a student registration number
• registration in other institutions

Here, the meaning is clearly the enrollment/registration of my son at school.

Because matrícula is a feminine singular noun, so its definite article is a.

• a matrícula = the enrollment / the registration

Also, the expression is normally said as fazer a matrícula, not just fazer matrícula in this context.

So the article is part of the natural phrase.

Because do is the contraction of:

• de + o = do

Here, the article o appears before the possessive meu filho, which is very common in Brazilian Portuguese.

So:

• de o meu filho → do meu filho

This structure means:

• of my son
• or more naturally in English here, my son’s

Using the article before possessives is very common in Brazilian Portuguese:

• o meu filho
• a minha filha
• os meus pais

So do meu filho sounds very natural.

That is a normal difference between English and Portuguese.

In Brazilian Portuguese, possessives are often used with a definite article:

• o meu filho
• a minha mãe
• os meus amigos

When another word like de comes before it, you get contractions:

• de + o meu filho → do meu filho

English does not do this, but Portuguese often does.

Important: the article with possessives is very common in Brazil, but in some contexts it can be omitted:

• meu filho
• o meu filho

Both can be correct, but in this sentence do meu filho is the most natural form.

Because na is the contraction of:

• em + a = na

Here, escola is feminine, so:

• a escola
• em a escola → na escola

In this sentence, na escola means at the school or in the school, depending on how English expresses it.

With matrícula, Portuguese commonly says:

• fazer a matrícula na escola
• matricular o filho na escola

So na escola is the normal choice.

Sometimes, but it changes the nuance.

• na escola focuses on the place/institution where the enrollment happens
• para a escola can sound more like for the school or to the school

With matrícula, Brazilian Portuguese very often uses em/no/na:

• matrícula na escola
• matricular na escola

So in this sentence, na escola is the most natural choice.

No, it does not have to be at the end.

You can place amanhã in different spots:

• Eu vou fazer a matrícula do meu filho na escola amanhã.
• Amanhã eu vou fazer a matrícula do meu filho na escola.
• Eu vou amanhã fazer a matrícula do meu filho na escola. ← possible, but less natural

The most common and natural choices are:

• at the beginning for emphasis on time
• at the end in neutral statements

So the original sentence sounds very natural.

Yes.

The phrase do meu filho makes it clear that the enrollment is for the speaker’s son.

So:

• Eu vou fazer a matrícula = I’m going to do the enrollment
• do meu filho = of my son / for my son

The speaker is the person doing the action, but the son is the person being enrolled.

Yes, absolutely.

That sentence is also correct and natural:

• Vou matricular meu filho na escola amanhã.

It uses the verb matricular directly instead of the expression fazer a matrícula.

Very roughly:

• fazer a matrícula do meu filho = do my son’s enrollment
• matricular meu filho = enroll my son

Both are common. The version with fazer a matrícula can sound a little more focused on the administrative process.

You may hear both, but they are not always exactly the same in usage.

• escola = school
• colégio = school, often used especially for primary/secondary private schools, depending on context

In many everyday situations in Brazil, people use both words naturally, but escola is the broader and safest general term.

So the original sentence with escola is perfectly standard.