El jugador mira el tauler.

Because Catalan uses the definite article el for masculine singular nouns, and here both nouns are masculine singular:

• el jugador = the player
• el tauler = the board

So the sentence literally has the player and the board, just like in English.

Catalan often uses articles in places where English does too, but it also uses them in some places where English might leave them out.

Jugador is the masculine form meaning player.
Jugadora is the feminine form.

So:

• el jugador = the male player
• la jugadora = the female player

If you are talking about a specific man or boy, jugador is correct. If the player is female, you would normally say la jugadora.

Mira is the third-person singular form of the verb mirar (to look at, to watch).

Present tense of mirar:

• jo miro = I look
• tu mires = you look
• ell / ella mira = he / she looks
• nosaltres mirem = we look
• vosaltres mireu = you all look
• ells / elles miren = they look

So El jugador mira el tauler uses mira because el jugador is he / the player.

It can mean both, depending on context.

In this sentence, mira el tauler is most naturally looks at the board.

Some useful comparisons:

• mirar una pel·lícula = to watch a film
• mirar el cel = to look at the sky

So mirar is a very flexible verb, much like Spanish mirar.

Because Catalan mirar usually takes a direct object. English often says look at something, but Catalan simply says mirar alguna cosa.

So:

• mira el tauler = literally looks the board
• natural English: looks at the board

This is very normal in Catalan. You do not need a separate word for at here.

Tauler usually means board. The exact translation depends on context.

It can refer to things like:

• a game board
• a board or panel
• sometimes a notice board or display board, depending on context

In a sentence with jugador (player), learners often understand tauler as a game board, such as in chess or another board game.

This is the normal subject + verb + object order:

• El jugador = subject
• mira = verb
• el tauler = direct object

This is the most straightforward and neutral word order in Catalan, just as in English:

• The player
  • looks at
    • the board

Catalan can sometimes change word order for emphasis, but this version is the basic one.

Yes. Catalan is a pro-drop language, which means the subject pronoun can often be omitted because the verb ending already gives information about the subject.

For example:

• Mira el tauler = He/She looks at the board or looks at the board

But in your sentence, El jugador is not a pronoun like he; it is a full noun phrase, the player. If you want to say specifically the player, you include it.

A simple learner-friendly guide:

• jugador ≈ zhoo-guh-DOR
• tauler ≈ tow-LAY or tow-LER, depending on accent

A few pronunciation notes:

• j in Catalan is usually like the s in measure or the j sound in some pronunciations of French jour, not the English j in jam
• the stress in jugador falls on the last syllable: -dor
• in tauler, the au is a diphthong, something like ow in cow, though the exact sound varies by dialect

Because el tauler is the direct object of mirar.

• el tauler = the board
• al tauler = to the board or at the board in a different grammatical structure

Since mirar takes a direct object, Catalan uses:

• mira el tauler

not

• mira al tauler

Using al here would sound nonstandard in normal Catalan.

Yes. Both the noun phrases and the verb can change depending on number.

Singular:

• El jugador mira el tauler.
  The player looks at the board.

Plural subject:

• Els jugadors miren el tauler.
  The players look at the board.

Plural object:

• El jugador mira els taulers.
  The player looks at the boards.

Both plural:

• Els jugadors miren els taulers.

Notice:

• el → els
• jugador → jugadors
• tauler → taulers
• mira → miren

Yes. It is fully grammatical and natural.

It is a simple present-tense sentence with:

• a definite subject
• a common verb
• a definite direct object

It sounds like the kind of example sentence used in textbooks to show basic Catalan grammar. Depending on context, a native speaker could easily say it.