Nel minibar c’è solo acqua frizzante e una piccola bottiglia di succo.

Nel is the normal contraction of in + il.

• in + il = nel
• So nel minibar means in the minibar

Italian often combines prepositions with definite articles:

• in + il = nel
• di + il = del
• a + il = al

Using in il minibar would sound wrong in standard Italian because the contraction is expected.

C’è means there is.

It is made from:

• ci = there
• è = is

So:

• c’è solo acqua frizzante... = there is only sparkling water...

This structure is very common in Italian for saying that something exists or is present somewhere:

• C’è un problema = There is a problem
• Ci sono due camere = There are two rooms

Because Italian uses c’è / ci sono to express there is / there are.

Compare:

• È acqua frizzante = It is sparkling water
• C’è acqua frizzante = There is sparkling water

In your sentence, the idea is not identifying something, but saying what is available in the minibar. That is why c’è is the natural choice.

Because acqua is being used as an uncountable noun in a general, indefinite sense.

• c’è solo acqua frizzante = there is only sparkling water

This is similar to English, where you usually say there is only water, not there is only a water.

If you added an article, the meaning would change:

• c’è solo l’acqua frizzante = there is only the sparkling water
  (more specific, referring to a particular water)
• c’è solo dell’acqua frizzante = there is only some sparkling water
  (possible, but less neutral here)

The version in the sentence is the most natural and simple.

In Italian, descriptive adjectives often come after the noun.

So:

• acqua frizzante = sparkling water
• vino rosso = red wine
• camera grande = big room

This is one of the common differences from English, where adjectives usually come before the noun.

Both are possible, but they can sound slightly different.

• una piccola bottiglia is the most natural here and simply means a small bottle
• una bottiglia piccola is possible, but it can sound more contrastive or descriptive, as if you are stressing the size more specifically

In Italian, some common adjectives—especially ones like piccolo, grande, buono, bello—often come before the noun in everyday speech.

So una piccola bottiglia sounds very normal.

Because bottiglia di succo means bottle of juice.

Here, di links the container to its contents:

• una bottiglia di succo = a bottle of juice
• un bicchiere di vino = a glass of wine
• una tazza di tè = a cup of tea

If you said del succo, that would usually mean some juice, which is a different structure.

So:

• una bottiglia di succo = a bottle of juice
• del succo = some juice

Yes. Minibar is commonly used in Italian as a borrowed word, especially in hotels.

It is treated as a masculine noun:

• il minibar
• nel minibar

Many modern Italian words, especially in travel and hospitality, come from English or international usage.

Solo means only.

In this sentence:

• c’è solo acqua frizzante e una piccola bottiglia di succo

it means that the minibar contains nothing except those items.

Its position is very natural in Italian. It comes before the things being limited:

• C’è solo acqua = There is only water
• Ho solo un minuto = I only have a minute

This is a very good question.

Strictly speaking, since two things are listed—acqua frizzante and una piccola bottiglia di succo—some speakers might expect ci sono.

However, c’è is still very common when the speaker is presenting the contents as a general amount or inventory, especially when the first item is an uncountable noun like acqua.

So in real Italian, c’è here sounds quite natural.

A more strictly plural version could be:

• Nel minibar ci sono solo acqua frizzante e una piccola bottiglia di succo.

Both can be heard, but the original sentence is perfectly normal.

If the sentence clearly referred to plural countable things, Italian would normally use ci sono instead of c’è.

For example:

• Nel minibar ci sono due bottiglie d’acqua. = There are two bottles of water.
• Nel minibar ci sono delle bibite. = There are some drinks in the minibar.

So the basic rule is:

• c’è = there is
• ci sono = there are

The apostrophe shows that ci è has been shortened to c’è.

This is very common in Italian when two vowels come together and the language prefers a contracted form.

So:

• ci è → c’è

You should learn c’è as the normal written form for there is.

Yes. Succo usually means juice, and very often it refers to fruit juice unless something else is specified.

Examples:

• succo d’arancia = orange juice
• succo di mela = apple juice
• succo by itself = juice

In your sentence, una piccola bottiglia di succo sounds like a small bottle of juice, with the exact type not specified.