O babador ficou sujo de papinha, então vou lavar agora.

Ficou sujo means became/got dirty, so it focuses on the change of state.

• O babador ficou sujo = the bib got dirty
• O babador está sujo = the bib is dirty

In this sentence, ficou is used because the idea is that the bib was clean before and then became dirty from the baby food.

Here, ficou is the past tense of ficar, and it means something like ended up, became, or got.

So:

• ficar sujo = to get dirty
• ficou sujo = got dirty

This is a very common structure in Portuguese:

• ficou cansado = got tired
• ficou triste = became sad
• ficou pronto = became ready / was finished

In Portuguese, sujo de + substance/material is very common when you say what something is dirty with.

• sujo de lama = dirty with mud
• sujo de tinta = dirty with paint
• sujo de comida = dirty with food

So sujo de papinha sounds very natural.

Using com is not impossible in every context, but sujo de is the usual and more idiomatic choice here.

Papinha is a diminutive form. In Brazilian Portuguese, -inho / -inha is often added to make a word sound:

• smaller
• cuter
• more affectionate
• more child-related

Here, papinha usually refers to baby food, especially soft mashed food or purée given to babies.

So the diminutive is very natural because this sentence is about a bib, which already suggests a baby context.

Portuguese often drops subject pronouns when the verb already makes the subject clear.

• (Eu) vou lavar agora
• I’m going to wash it now

Because vou is clearly the first person singular form, native speakers usually do not need to say eu.

Including eu is possible, but it often adds emphasis:

• Eu vou lavar agora. = I’m the one who’s going to wash it now.

The object is understood from context: the bib.

Portuguese often leaves out words that are obvious from the situation.

So vou lavar agora naturally means:

• I’m going to wash it now

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

• vou lavar o babador agora

You could also use a pronoun, but in everyday Brazilian Portuguese that is often avoided in casual speech.

Yes, grammatically you can say vou lavá-lo agora, meaning I’m going to wash it now.

But in everyday spoken Brazilian Portuguese, this sounds more formal or more written than:

• vou lavar agora
• vou lavar o babador agora

Brazilian Portuguese often prefers either:

1. leaving the object implied, or
2. repeating the noun

So for natural casual speech, the original sentence sounds very normal.

Então here means so or therefore.

It connects the two ideas:

• the bib got dirty with baby food
• so I’m going to wash it now

It is very common in spoken and written Portuguese for introducing a result or consequence.

Examples:

• Está chovendo, então vou ficar em casa.
• I’m tired, so I’m going to sleep.

Agora means now, and putting it at the end is very natural in Portuguese.

• vou lavar agora
• agora vou lavar

Both are possible, but they can feel slightly different in emphasis:

• vou lavar agora = neutral, very natural
• agora vou lavar = emphasizes now

So the original sentence sounds completely normal and conversational.

Yes. Babador is the normal word for bib in Brazilian Portuguese.

It comes from babar, which means to drool. So a babador is literally something related to drooling, which makes sense for babies.

This is the standard everyday word a Brazilian would normally use.

Yes, it sounds very natural and everyday.

A Brazilian parent or caregiver could easily say:

• O babador ficou sujo de papinha, então vou lavar agora.

It sounds casual, clear, and idiomatic. The vocabulary and grammar are both very typical of spoken Brazilian Portuguese.