Hoje eu vou colocar a roupa na máquina e usar um pouco de amaciante.

This is the very common near future structure in Brazilian Portuguese:

ir + infinitive
→ vou colocar = I’m going to put

So eu vou colocar is often more natural in everyday speech than the simple future colocarei.

• Hoje eu vou colocar... = natural, conversational Brazilian Portuguese
• Hoje eu colocarei... = grammatically correct, but more formal or less common in casual speech

The same thing happens with usar in this sentence: it is also part of that future idea.

Yes, eu is optional here.

Portuguese verbs often already show the subject, so:

• Hoje eu vou colocar...
• Hoje vou colocar...

Both are correct.

Native speakers may include eu for:

• emphasis
• clarity
• rhythm
• contrast with someone else

So in this sentence, eu is not required, but it sounds completely natural.

In Portuguese, roupa can work as a kind of collective noun meaning clothes or laundry in general.

So:

• a roupa = the clothes / the laundry
• as roupas = the clothes, with more emphasis on individual items

When talking about laundry, a roupa is very common and natural in Brazilian Portuguese.

So colocar a roupa na máquina usually means put the laundry/clothes in the washing machine.

Na is a contraction:

• em + a = na

So:

• na máquina = in the machine

In this context, máquina normally means washing machine, even though the full expression would be máquina de lavar.

So literally:

• colocar a roupa na máquina = put the clothes in the machine

Because one conjugated verb can govern two infinitives joined by e.

So:

• vou colocar a roupa na máquina e usar um pouco de amaciante

means:

• I’m going to put the clothes in the machine and use a little fabric softener

Portuguese does not need to repeat vou if the same subject and same future idea continue.

You could also say:

• Hoje eu vou colocar a roupa na máquina e vou usar um pouco de amaciante.

That is also correct, but slightly more repetitive.

Um pouco de means a little or some.

It is a fixed expression:

• um pouco de água = a little water
• um pouco de açúcar = a little sugar
• um pouco de amaciante = a little fabric softener

The de is required after um pouco when it introduces the thing you mean.

So you should think of um pouco de as one chunk.

After um pouco de, Portuguese often uses the noun without an article when speaking generally or indefinitely.

So:

• um pouco de amaciante = a little fabric softener

If you wanted to refer to a specific, known softener, you might hear:

• um pouco do amaciante

That means something more like a little of the fabric softener.

In your sentence, um pouco de amaciante is the most natural general wording.

Amaciante means fabric softener.

It comes from the verb amaciar, which means to soften.

In laundry context, amaciante is often short for:

• amaciante de roupas = fabric softener

So this is very normal everyday vocabulary in Brazilian Portuguese.

Because context does a lot of work in Portuguese, just like in English.

In a laundry sentence, if someone says:

• colocar a roupa na máquina

native speakers naturally understand washing machine.

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

• colocar a roupa na máquina de lavar

But in ordinary conversation, máquina is often enough.

Yes. Portuguese word order is fairly flexible, especially with time expressions like hoje.

All of these are possible:

• Hoje eu vou colocar a roupa na máquina e usar um pouco de amaciante.
• Eu vou colocar a roupa na máquina hoje e usar um pouco de amaciante.
• Eu vou colocar a roupa na máquina e usar um pouco de amaciante hoje.

Putting Hoje at the beginning is very common because it sets the time frame right away.

Not exactly.

• colocar a roupa na máquina = to put the clothes/laundry into the washing machine
• lavar a roupa = to wash the clothes / do the laundry

So colocar a roupa na máquina describes one step in the process, while lavar a roupa is the broader action.

In real life, though, if someone says vou colocar a roupa na máquina, it often strongly implies they are about to start a wash cycle.

Yes, absolutely.

• Hoje eu vou colocar a roupa na máquina e usar um pouco de amaciante.
• Hoje vou colocar a roupa na máquina e usar um pouco de amaciante.

Both sound natural.

Brazilian Portuguese often uses subject pronouns more than some other varieties of Portuguese, but omitting eu here is still completely normal.