Na okładce widzę ten sam tytuł, który był już w gazecie obok zdjęcia aktorki.

Because na here means on in a static location sense, and after na Polish uses the locative case when something is located somewhere.

• dictionary form: okładka = cover
• locative singular: okładce

So:

• na okładce = on the cover

If movement were involved, Polish might use a different case, but here the title is simply being seen on the cover.

Widzę is the 1st person singular present tense of widzieć (to see).

So:

• widzę = I see

It matches an understood subject I, which Polish often leaves unstated because the verb ending already tells you who the subject is.

Because widzieć takes a direct object, and direct objects are usually in the accusative case.

Here the object is ten sam tytuł = the same title.

A useful detail:

• tytuł is masculine inanimate
• in the accusative singular, masculine inanimate nouns and their adjectives/demonstratives usually look the same as in the nominative

So:

• nominative: ten sam tytuł
• accusative: ten sam tytuł

That is why the form does not visibly change.

Ten sam means the same.

It is a very common Polish structure:

• ten sam tytuł = the same title
• ta sama książka = the same book
• to samo zdjęcie = the same photo

The words must agree with the noun in gender, number, and case.

Here:

• tytuł is masculine singular
• so we get ten sam

Because który introduces a relative clause.

The clause:

• który był już w gazecie obok zdjęcia aktorki

describes tytuł. In Polish, relative clauses like this are normally separated by a comma.

So the sentence structure is:

• main clause: Na okładce widzę ten sam tytuł
• relative clause: który był już w gazecie obok zdjęcia aktorki

Because który refers back to tytuł and functions as the subject of the relative clause.

In the clause:

• który był już w gazecie...
• which was already in the newspaper...

the title is the thing that was there. Since it is the subject, Polish uses the nominative form:

• masculine singular nominative: który

If it had a different role in the clause, you would see a different case form, such as którego, któremu, etc.

Był is the past tense of być (to be), masculine singular, matching tytuł.

So:

• który był już w gazecie = which was already in the newspaper

The word już means already. It suggests that the title had appeared there earlier.

Word order with już is somewhat flexible, but był już sounds natural here.

Because w (in) takes the locative when it expresses location.

• dictionary form: gazeta = newspaper
• locative singular: gazecie

So:

• w gazecie = in the newspaper

This is similar to:

• w książce = in the book
• w szkole = at school / in the school

This is a very common Polish pattern.

1. obok takes the genitive

The preposition obok means next to / beside and normally requires the genitive.

So:

• zdjęcie → zdjęcia

Hence:

• obok zdjęcia = next to the photo

2. aktorki is also genitive

In zdjęcie aktorki, the second noun tells you whose photo it is or what the photo is of.

• aktorka → aktorki

So:

• zdjęcie aktorki = a photo of the actress / the actress’s photo

Put together:

• obok zdjęcia aktorki = next to the actress’s photo

Most naturally, it describes the location in the newspaper:

• the title was in the newspaper, next to the actress’s photo

So the likely grouping is:

• [był już [w gazecie obok zdjęcia aktorki]]

In other words, obok zdjęcia aktorki goes with w gazecie as part of the location.

Grammatically, word order can sometimes leave small ambiguities in Polish, but this is the most natural reading.

Because Polish has no articles.

English says:

• on the cover
• the same title
• in the newspaper
• next to the actress’s photo

Polish usually expresses definiteness through:

• context
• word order
• demonstratives like ten

So ten sam tytuł helps make the noun specific, but Polish still does not use a separate word exactly equivalent to the.

Yes. Polish word order is quite flexible, because case endings show grammatical relationships.

This sentence begins with Na okładce to foreground the location:

• Na okładce widzę ten sam tytuł...

A more neutral-looking order might be:

• Widzę na okładce ten sam tytuł...

Both are grammatical, but the original version puts a little more attention on the cover.

A few words may be tricky for English speakers:

• widzę: the ę is a nasal vowel; at the end of a word it is often pronounced less strongly nasal than learners expect
• okładce: the cluster dc can be awkward at first
• zdjęcia: zdj- is a challenging cluster; learners often need practice saying it smoothly
• który: the ó sounds like u
• aktorki: stress is on the second-to-last syllable: ak-TOR-ki

Also remember that Polish stress is usually on the penultimate syllable, which helps with most words in this sentence.