Em outubro, depois do trabalho, eu volto a rever a primeira avaliação com calma.

With months in Portuguese, em + month is the normal way to say in a given month:

• em outubro = in October
• em janeiro = in January

Portuguese does not usually use an article before the month name in this kind of expression, so no outubro would sound wrong here.

Literally, it means after the work, but in natural English it is usually understood as after work or after my workday.

The form do is a contraction:

• de + o = do

So:

• depois de o trabalho → depois do trabalho

Yes, it can often be left out.

Portuguese is a pro-drop language, which means the subject pronoun is often omitted when the verb ending already makes the subject clear.

So both are possible:

• Eu volto a rever...
• Volto a rever...

Including eu can add:

• emphasis,
• contrast,
• or just a slightly more explicit style.

This is a very common structure in Portuguese:

• voltar a + infinitive

It means:

• to do something again
• to go back to doing something

So:

• volto a rever = I review again / I go back to reviewing

In this sentence, rever already means to review / to look at again, so volto a rever gives the idea of going back to review it again, often with a sense of returning to the task.

Because the verb pattern is:

• voltar a + infinitive

So:

• volto a estudar = I study again
• volto a ler = I read again
• volto a rever = I go back to reviewing

That a is a preposition required by voltar in this structure. It is not the feminine article a meaning the.

• ver = to see
• rever = to see again, review, re-examine

So rever often means more than just physically seeing something again. It can mean:

• reviewing a document,
• going over notes,
• rechecking an evaluation,
• reconsidering something.

In this sentence, rever a primeira avaliação most naturally means to review the first assessment/evaluation again.

Because avaliação is a feminine singular noun, so it takes:

• a = the
• primeira = first, in the feminine singular form

Agreement matters in Portuguese:

• o primeiro livro = the first book
• a primeira avaliação = the first evaluation

Both the article and the adjective must match the noun in gender and number.

Avaliação can mean several things depending on context, such as:

• evaluation
• assessment
• review
• appraisal

In an academic context, it might be assessment.
In a workplace or performance context, it might be evaluation or appraisal.

So the exact English word depends on the situation, even though the Portuguese word stays the same.

Literally it does mean with calm, but idiomatically it means:

• calmly
• carefully
• without rushing
• at ease

So rever ... com calma means something like:

• to review ... carefully
• to go over it calmly
• to look at it properly, without rushing

This is a very common Portuguese expression.

Yes, the word order is natural.

The sentence begins with time expressions and a situational phrase:

• Em outubro = in October
• depois do trabalho = after work

Then comes the main clause:

• eu volto a rever a primeira avaliação com calma

The commas separate introductory elements, making the sentence easier to read. Portuguese often uses commas this way when fronting time or context phrases.

A simpler order could also be:

• Eu volto a rever a primeira avaliação com calma em outubro, depois do trabalho.

But the original version puts the time and setting first, which is very natural.

In theory, trabalho can mean work, job, or piece of work, but here depois do trabalho is most naturally understood as:

• after work
• after the workday
• after finishing work

If someone meant after the job/project, context would usually make that clear.

Sometimes, but the meaning changes slightly.

• revejo a primeira avaliação = I review the first evaluation
• volto a rever a primeira avaliação = I review the first evaluation again / I go back to reviewing it

So volto a rever adds the idea of returning to the action. It is not just the action itself, but doing it again after some interruption or previous attempt.

The sentence works in both, but it feels especially natural in European Portuguese because voltar a + infinitive is very common there.

Brazilian Portuguese would also understand it perfectly, but depending on context, a Brazilian speaker might also say something like:

• eu volto a revisar...
• eu revejo...
• eu vou rever de novo...

Also, avaliação is used in both varieties, though the most natural translation into English may still depend on context.

A useful breakdown is:

• Em outubro = time expression
• depois do trabalho = additional time/context expression
• eu = subject
• volto a rever = verb phrase
• a primeira avaliação = direct object
• com calma = adverbial expression describing how the action is done

So the structure is roughly:

[time] + [time/context] + [subject] + [verb phrase] + [object] + [manner]

That makes it easier to see how the sentence is built.