Em abril, nós costumamos viajar no feriado e descansar na praia.

Because with months, Portuguese normally uses em without an article:

• em abril = in April
• em maio = in May
• em dezembro = in December

So Em abril is the normal way to say in April.

In Portuguese, months of the year are normally written in lowercase:

• abril
• junho
• novembro

This is different from English, where April is capitalized.

Em abril is a time expression placed at the beginning of the sentence. The comma helps separate that introductory phrase from the main clause.

So both of these are possible:

• Em abril, nós costumamos viajar...
• Em abril nós costumamos viajar...

The comma is very common and helps readability, especially in writing.

Not always. In Portuguese, the verb ending often already shows the subject.

• costumamos already means we usually
• so Nós costumamos... and Costumamos... can both work

Including nós can add clarity, emphasis, or just sound more complete in some contexts.

In everyday Brazilian Portuguese, another very common option is:

• A gente costuma viajar...

That also means we usually travel..., but it takes a third-person singular verb.

Costumamos is the first-person plural present form of costumar.

Costumar + infinitive means:

• to usually do something
• to tend to do something
• to have the habit of doing something

So:

• nós costumamos viajar = we usually travel

It expresses a habit or repeated action, not something happening right now.

This is an important distinction.

• costumar + infinitive = to usually do
• estar acostumado a + noun/infinitive = to be used to

Examples:

• Costumo acordar cedo. = I usually wake up early.
• Estou acostumado a acordar cedo. = I am used to waking up early.

So in your sentence, costumamos viajar means we usually travel, not we are used to traveling.

Because after costumar, the next verb stays in the infinitive.

Pattern:

• costumar + infinitive

So:

• costumamos viajar
• costumamos descansar

In the sentence, one costumamos controls both verbs:

• costumamos viajar ... e descansar ...

That is very natural in Portuguese.

Using costumamos makes the idea of habit very explicit.

Compare:

• Nós viajamos no feriado. = We travel on the holiday / We do travel on the holiday
• Nós costumamos viajar no feriado. = We usually travel on the holiday

The second one clearly emphasizes routine or habit.

No is a contraction:

• em + o = no

So no feriado literally comes from em o feriado.

It usually means:

• on the holiday
• during the holiday
• sometimes over the holiday weekend

Portuguese very often contracts em with definite articles:

• no = em + o
• na = em + a
• nos = em + os
• nas = em + as

Not exactly.

In Brazilian Portuguese, feriado usually means a public holiday or day off such as:

• Easter-related holidays
• Tiradentes
• Christmas Day

It can also imply a long weekend when people travel.

It does not usually mean vacation in the general English sense. For vacation/time off from work or school, Portuguese usually uses:

• férias

So this sentence is about traveling on a holiday, not necessarily during a vacation.

Because na praia shows location:

• na = em + a
• na praia = at/on the beach

Here, the idea is resting at the beach, so a location expression is needed.

Compare:

• descansar na praia = to rest at the beach
• ir à praia = to go to the beach

So:

• na praia = where the resting happens
• à praia = destination after a verb of movement like ir

Because both actions share the same subject and the same idea of habit.

So Portuguese can say:

• nós costumamos viajar no feriado e descansar na praia

This is like saying:

• we usually travel on the holiday and rest at the beach

Repeating costumamos is possible, but it sounds heavier and is usually unnecessary:

• nós costumamos viajar no feriado e costumamos descansar na praia

The version with only one costumamos is more natural.

Yes. A very common spoken version would be:

• Em abril, a gente costuma viajar no feriado e descansar na praia.

Why?

• a gente is extremely common in spoken Brazilian Portuguese for we
• it takes the verb in the third-person singular:
  • a gente costuma
  • not a gente costumamos

Your original sentence is completely correct, but a gente often sounds more conversational in Brazil.