Tengo que renovar el pasaporte hoy mismo.

Tengo by itself means I have.
To say I have to + verb, Spanish uses tener que + infinitive.

So:

• tengo = I have
• tengo que renovar = I have to renew

This is one of the most common ways to express obligation in Spanish.

Tengo is the first person singular form of tener in the present tense.

• tener = to have
• tengo = I have

It is irregular, so it does not follow a fully regular pattern.

For reference:

• yo tengo = I have
• tú tienes = you have
• él/ella tiene = he/she has
• nosotros tenemos = we have
• vosotros tenéis = you all have
• ellos tienen = they have

Because after tener que, the next verb stays in the infinitive.

Pattern:

• tener que + infinitive

Examples:

• Tengo que estudiar = I have to study
• Tenemos que salir = We have to leave
• Tengo que renovar el pasaporte = I have to renew the passport

Only the first verb (tener) is conjugated here.

Yes. Renovar means to renew, and it is the normal verb to use for things like:

• renovar el pasaporte = renew the passport
• renovar el carné de conducir = renew your driving licence
• renovar un contrato = renew a contract
• renovar una suscripción = renew a subscription

So in this sentence, renovar is the natural choice.

Spanish often uses the definite article (el, la, los, las) where English would use a possessive like my or your, especially when the owner is obvious from context.

Here, tengo que renovar el pasaporte naturally means I have to renew my passport.

Using mi pasaporte is possible, but it usually sounds more explicit or contrastive:

• Tengo que renovar mi pasaporte, no el tuyo.
  = I have to renew my passport, not yours.

So el pasaporte is very normal and natural.

Because pasaporte is a masculine noun in Spanish, so it takes el.

• el pasaporte

A useful clue is that many nouns ending in -e can be either masculine or feminine, so you usually have to learn the gender with the noun itself.

Hoy mismo adds emphasis. It means something like:

• today itself
• today, no later
• today, right away / as soon as possible today

It is stronger than just hoy.

Compare:

• Tengo que renovar el pasaporte hoy.
  = I have to renew the passport today.
• Tengo que renovar el pasaporte hoy mismo.
  = I have to renew the passport today itself / today without fail.

So mismo adds urgency or emphasis.

In this sentence, hoy mismo works as a fixed expression, and this is the most natural position.

• Tengo que renovar el pasaporte hoy mismo.

You will often see mismo used for emphasis with time expressions:

• ahora mismo = right now
• hoy mismo = today itself / today without delay
• esta noche mismo is not standard; usually esta misma noche = this very night

So with hoy, the normal phrase is hoy mismo.

Yes. Debo renovar el pasaporte hoy mismo is grammatically correct and means nearly the same thing.

But there is often a slight difference in feel:

• tener que = the most common, everyday way to say have to
• deber = can sound a bit more formal, more like must / ought to, depending on context

In everyday Spanish, especially spoken Spanish, tengo que is extremely common and very natural.

Yes, to some extent. The most neutral order is:

• Tengo que renovar el pasaporte hoy mismo.

You could also move the time phrase for emphasis:

• Hoy mismo tengo que renovar el pasaporte.

This gives more focus to today itself.

But the original order is the most straightforward and natural in many contexts.

In standard Peninsular Spanish, it would sound roughly like:

TEN-go ke reh-no-BAR el pah-sa-POR-te oy MEES-mo

A few useful pronunciation notes:

• g in tengo is a hard g sound, like in go
• que sounds like keh
• r in renovar is a tapped/flapped r
• v in renovar is pronounced like a soft Spanish b sound, not like an English v
• z does not appear here, so there is no special Spain-only th sound in this sentence
• stress falls on:
  • TEN-go
  • reh-no-BAR
  • pah-sa-POR-te
  • HOY
  • MIS-mo

Yes, and that is exactly what happens in the sentence.

Spanish usually does not need the subject pronoun when the verb already shows who the subject is.

• (Yo) tengo que renovar el pasaporte hoy mismo.

Both are correct, but the version without yo is more natural unless you want emphasis or contrast:

• Yo tengo que renovar el pasaporte hoy mismo, no tú.

So omitting yo is normal.

Yes. Tengo is in the present tense, but tener que + infinitive expresses a present obligation about an action that may happen in the future.

So:

• Tengo que renovar el pasaporte hoy mismo.

means that right now, you are under the obligation to renew it, and the renewal still has to happen.

This is completely normal in both Spanish and English:

• I have to renew it today
  is also present tense plus future-oriented meaning.