No sé cocinar pasta, pero quiero aprender.

Because sé and se are two different words.

• sé = I know (from saber)
• se = a pronoun used in many other structures

The accent mark helps distinguish them in writing. In this sentence, No sé cocinar pasta means I don’t know how to cook pasta, so it has to be sé.

Spanish often leaves out subject pronouns when the verb already shows who the subject is.

• sé already means I know
• quiero already means I want

So No sé cocinar pasta, pero quiero aprender naturally means I don’t know how to cook pasta, but I want to learn without needing yo.

You could say Yo no sé cocinar pasta, pero quiero aprender, but that usually adds emphasis, as if you are contrasting yourself with someone else.

In Spanish, saber + infinitive often means to know how to do something.

So:

• sé cocinar = I know how to cook
• no sé cocinar = I don’t know how to cook

This is a very common pattern. Compare:

• Sé nadar = I know how to swim
• No sabe conducir = He/She doesn’t know how to drive

Because after saber in this structure, Spanish uses an infinitive.

• sé cocinar
• quiero aprender

This works a lot like English:

• I know how to cook
• I want to learn

The infinitive is the basic verb form, like to cook, to learn, to eat.

After querer, Spanish uses the infinitive, not a conjugated verb.

So:

• quiero aprender = I want to learn
• not quiero aprendo

This is the same pattern as:

• quiero comer = I want to eat
• quiero viajar = I want to travel

Spanish often expresses to know how to do something simply as saber + infinitive, without needing a separate word for how.

So:

• No sé cocinar pasta literally looks like I don’t know to cook pasta
• but the real meaning is I don’t know how to cook pasta

Likewise, quiero aprender can imply I want to learn (how) from the context.

Because Spanish can leave that understood from context, just like English.

In this sentence, aprender clearly refers to learning how to cook pasta, because that idea was just mentioned.

If you want to be more explicit, you could say:

• No sé cocinar pasta, pero quiero aprender a cocinarla.
• No sé cocinar pasta, pero quiero aprender a cocinar pasta.

Notice that when you specify the action after aprender, you often use aprender a + infinitive:

• aprender a cocinar
• aprender a nadar
• aprender a conducir

Because pero is the normal word for but when you are adding a contrast.

• No sé cocinar pasta, pero quiero aprender. = I don’t know how to cook pasta, but I want to learn.

Sino is used in a more specific correction pattern, usually after a negative statement, meaning something like but rather:

• No quiero té, sino café. = I don’t want tea, but rather coffee.

In your sentence, the second part is not correcting the first part; it is just contrasting with it. So pero is correct.

Here, pasta clearly means pasta as food.

In some informal contexts, pasta can also mean money, especially in Spain, but the verb cocinar makes the meaning obvious here. You cook pasta, not money.

So in this sentence, there is no ambiguity.

Sometimes, but the meaning can shift.

• cocinar pasta = to cook pasta
• hacer pasta can mean to make pasta, especially from scratch, depending on context

If you mean preparing a pasta dish in general, cocinar pasta works well. If you mean actually making the pasta itself, especially homemade pasta, hacer pasta may be more natural.

For a learner, cocinar pasta is perfectly understandable and correct.

In Spanish, a comma is commonly used before pero when it joins two clauses.

So:

• No sé cocinar pasta, pero quiero aprender.

This is standard punctuation and helps separate the two contrasting ideas.

A simple pronunciation guide:

• sé sounds roughly like seh
• quiero sounds roughly like KYEH-ro
• cocinar sounds roughly like ko-thee-NAR in much of Spain, or ko-see-NAR in Latin America
• pasta sounds like PAHS-ta
• pero sounds like PEH-ro
• aprender sounds like a-pren-DER

In Spain Spanish, the c before i in cocinar is often pronounced like the th in thin.

Yes, it is completely natural and correct in Spain Spanish.

A native speaker in Spain could say this exactly as it is:

No sé cocinar pasta, pero quiero aprender.

It sounds clear, everyday, and idiomatic.