Nosotras queremos sentarnos más atrás para ver mejor la pantalla.

Nosotras is the feminine plural form of we. It is used when the group is all female.

• nosotras = we (all women / girls)
• nosotros = we (a mixed group or all males)

So this sentence tells you that the speakers are female. If the group were mixed, Spanish would normally use nosotros.

Also, Spanish often drops subject pronouns, so Nosotras queremos... could simply be Queremos... if the context is clear.

Yes. Spanish usually omits subject pronouns because the verb ending already shows who is doing the action.

So both of these are correct:

• Nosotras queremos sentarnos más atrás...
• Queremos sentarnos más atrás...

Including nosotras can add emphasis, contrast, or clarity. For example, it may stress we as opposed to someone else.

The verb querer is a stem-changing verb in the present tense, but the stem change does not happen in the nosotros/nosotras and vosotros/vosotras forms.

Present tense of querer:

• quiero
• quieres
• quiere
• queremos
• queréis
• quieren

So queremos is the correct form for nosotras.

Sentarnos is made up of:

• sentar = to seat
• sentarse = to sit down
• nos = ourselves / us

Here, the full infinitive is sentarse, a reflexive verb meaning to sit down.
When the subject is nosotras, the reflexive pronoun is nos.

So:

• sentarnos = to sit down / to seat ourselves

In this sentence, it follows queremos, so the meaning is we want to sit down.

Yes. Both are correct.

• Queremos sentarnos más atrás
• Nos queremos sentar más atrás

With a conjugated verb + an infinitive, the reflexive pronoun can usually go:

1. attached to the infinitive: sentarnos
2. before the conjugated verb: nos queremos sentar

Both mean the same thing. In many contexts, queremos sentarnos sounds slightly neater, but both are natural.

Yes, atrás means back / behind / in the back, but más atrás means further back.

So:

• atrás = in the back / back there
• más atrás = further back

This is very natural in Spanish when talking about position in a room, cinema, theatre, classroom, etc.

This is a very common question.

• atrás usually refers to a position further back in general space
• detrás usually means behind something or someone

In a seating situation, más atrás is the natural choice because you mean further back in the room.

Examples:

• Queremos sentarnos más atrás. = We want to sit further back.
• Está detrás de la puerta. = It is behind the door.

So detrás often needs de + noun/pronoun, while atrás works well for general location.

Para introduces purpose here. It means in order to or so that.

• para ver mejor la pantalla = in order to see the screen better

This is a very common Spanish pattern:

• Estudio para aprender. = I study in order to learn.
• Fuimos temprano para encontrar sitio. = We went early to find a seat.

It is para, not por, because the sentence is expressing a goal or purpose.

Because ver means to see, while mirar means to look at.

In this sentence, the idea is about the result: being able to see the screen better. That is why ver fits best.

• ver = to see
• mirar = to look at

If you say para mirar la pantalla, it would sound more like to look at the screen, focusing on the action of looking rather than on seeing it clearly.

Mejor is the comparative form of bien and bueno. Here it works as an adverb modifying ver.

• bien = well
• mejor = better

So:

• ver mejor = to see better

You do not say más mejor in standard Spanish, just as you do not say more better in standard English.

And más bien usually means something like rather or more accurately, so it would not fit here.

Spanish usually uses the definite article when the thing is specific and understood from context.

Here, la pantalla means the screen — the screen that everyone knows you are talking about, such as the cinema screen, presentation screen, or TV screen.

Using la is completely normal and expected here.

They are related, but not exactly the same form.

• sentarse = the dictionary form, to sit down
• sentarnos = to sit down ourselves / to sit down, with nos attached for we

So sentarse is the general infinitive, while sentarnos is the infinitive adapted to the subject nosotras.

It would be understood everywhere in the Spanish-speaking world, and it sounds natural in Spain.

A few notes:

• nosotras is standard everywhere
• queremos sentarnos is standard everywhere
• más atrás is very widely used
• pantalla is standard for screen

So this sentence is not uniquely Spanish from Spain, but it is perfectly good Spanish for Spain.