Vamos a comenzar ahora.

It is a very common Spanish structure: ir a + infinitive.

• vamos = we go / we are going
• a comenzar = to begin

Together, vamos a comenzar means we are going to begin.

In real usage, it can also sound like let’s begin now, especially when a speaker is announcing the start of something.

Because this is a fixed grammar pattern: ir a + infinitive.

So you say:

• voy a hablar
• vas a salir
• vamos a comenzar

You cannot normally leave out the a here.
So vamos comenzar ahora would be incorrect.

Because after vamos a, Spanish uses the infinitive.

So:

• Vamos a comenzar ahora = We are going to begin now
• Comenzamos ahora = We begin now / We’re beginning now

Both are possible, but they are different structures.

Spanish often leaves out subject pronouns when they are clear from the verb ending.

• vamos already tells you the subject is we
• so nosotros is unnecessary

You could say Nosotros vamos a comenzar ahora, but it usually sounds more natural without nosotros unless you want extra emphasis, contrast, or clarity.

Yes, in most everyday situations they mean the same thing: to begin / to start.

So these are both natural:

• Vamos a comenzar ahora
• Vamos a empezar ahora

A common learner tip:

• empezar often feels a little more everyday and conversational
• comenzar can sound slightly more formal or polished

But the difference is small, and both are very common.

Yes. Comencemos ahora is also correct, and it means something like Let’s begin now.

The difference is mainly in style:

• Vamos a comenzar ahora = more neutral, very common in speech
• Comencemos ahora = more direct, a bit more formal or deliberate

So if a teacher, presenter, or host says Vamos a comenzar ahora, it sounds very natural.

Yes. Ahora is flexible.

All of these are possible:

• Vamos a comenzar ahora
• Ahora vamos a comenzar

They mean basically the same thing, but the emphasis changes slightly:

• Vamos a comenzar ahora puts the main idea first, then adds now
• Ahora vamos a comenzar highlights now from the start

The version in your sentence sounds very natural.

Vamos is the first-person plural form of the verb ir (to go).

Present tense of ir:

• voy = I go
• vas = you go
• va = he/she goes
• vamos = we go
• vais = you all go
• van = they go

In vamos a comenzar, Spanish uses this form of ir as part of the future-like expression ir a + infinitive.

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

So comenzar sounds approximately like:

• ko-men-THAR

A few notes:

• co as in coh
• men with a clear Spanish e
• zar with Spanish z = th sound in much of Spain

In many Latin American accents, that z would sound like s instead.

It is mostly neutral.

• It is natural in class, meetings, presentations, videos, guided activities, and everyday situations.
• comenzar may sound a little more formal than empezar, but not dramatically so.

So Vamos a comenzar ahora is a very normal, useful sentence that works in many contexts.