In bagno uso poca candeggina e poi passo il mocio con calma.

Italian often drops subject pronouns when they are not needed.

• uso already means I use
• passo already means I pass / I go over / I mop

The verb ending -o tells you the subject is I, so io is usually omitted unless you want emphasis or contrast.

• (Io) uso poca candeggina
• (Io) passo il mocio

If you said io uso..., it would sound more emphatic, like I use...

Because candeggina is a feminine singular noun, so poco has to agree with it.

Agreement:

• poco = masculine singular
• poca = feminine singular
• pochi = masculine plural
• poche = feminine plural

So:

• poca candeggina = a little bleach

This is the same kind of agreement you see in:

• poca acqua
• poca pazienza
• poco sapone
  because sapone is masculine

Here candeggina is being used as an uncountable substance, like bleach in English. In Italian, when talking about an unspecified amount of a substance, you often do not use an article.

So:

• uso poca candeggina = I use a little bleach

You could also say:

• uso della candeggina

Both are possible, but poca candeggina directly emphasizes the small quantity.

In bagno here means something like in the bathroom or when I’m in the bathroom / for the bathroom depending on context.

Italian often uses short location phrases like:

• in cucina
• in camera
• in bagno

These can sound natural and general.

Nel bagno is also possible, but it usually sounds a bit more specific:

• nel bagno = in the bathroom / inside that bathroom

So:

• In bagno uso poca candeggina sounds like a general statement about what I do in the bathroom.
• Nel bagno uso poca candeggina sounds slightly more tied to a specific bathroom.

Candeggina means bleach, usually the household cleaning product.

It is:

• feminine
• usually treated as an uncountable noun

So you will commonly see:

• la candeggina
• un po’ di candeggina
• poca candeggina

Poi means then, after that, or afterwards.

In this sentence it links the two actions in sequence:

1. uso poca candeggina
2. poi passo il mocio

So it shows the order:

• first I use a little bleach
• then I mop

Literally, passare il mocio is something like to pass the mop over a surface.

Naturally, in English, it usually means:

• I mop
• I go over it with the mop

The verb passare is very flexible in Italian. In cleaning contexts, it often means to run something over a surface.

Examples:

• passare l’aspirapolvere = to vacuum
• passare lo straccio = to wipe with a cloth
• passare il mocio = to mop

Yes, mocio is masculine singular, so it takes il:

• il mocio

That is why the sentence says:

• passo il mocio

The article is normal here because il mocio is the tool being used. Italian often keeps the article in expressions like this.

Yes. That would be a fuller version:

• passo il mocio sul pavimento = I mop the floor / I run the mop over the floor

In your sentence, sul pavimento is simply omitted because it is obvious from context. When someone says passare il mocio, the floor is usually understood.

Con calma literally means with calm, but in natural English it usually means:

• slowly
• carefully
• without rushing
• taking my time

So passo il mocio con calma suggests the speaker is not hurrying and is doing it in a careful, relaxed way.

It is a very common expression in Italian.

Examples:

• Parla con calma. = Speak calmly / Take it easy when speaking.
• Facciamo tutto con calma. = Let’s do everything without rushing.

It can be either, depending on context, but most naturally it sounds like a habit or usual way of doing things.

• In bagno uso poca candeggina e poi passo il mocio con calma.

This sounds like:

• In the bathroom, I use a little bleach and then I mop carefully.

So the present tense in Italian, just like in English, is often used for routines, habits, and general statements.

Yes, absolutely.

Both are natural, but they are slightly different in feel:

• poca candeggina = little bleach, not much bleach
• un po’ di candeggina = a bit of bleach

Poca emphasizes small quantity a bit more directly.
Un po’ di sounds a little softer and very common in everyday speech.

So all of these are natural:

• uso poca candeggina
• uso un po’ di candeggina

Because poi is a very common and natural word for then in everyday Italian.

• e poi = and then

You can also say dopo, but e poi is extremely common in speech and writing when listing actions in sequence.

So:

• e poi passo il mocio = and then I mop

It sounds very natural and conversational.