רציתי להשיג כרטיסים להופעה, אבל כבר לא נשארו.

Because רציתי is the past tense, first person singular form of the verb לרצות (to want).

• רציתי = I wanted
• the ending ־תי often marks I in the past tense

So:

• רציתי = I wanted
• רצית = you wanted (to a male)
• רציתָ / רציתְ distinctions are usually not written without vowel marks, but in speech they differ
• רצה = he wanted
• רצתה = she wanted

In this sentence, רציתי להשיג... means I wanted to get...

After רציתי (I wanted), Hebrew usually uses another verb in the infinitive to say what the person wanted to do.

So:

• רציתי להשיג = I wanted to get / obtain
• literally: I wanted to obtain

This is very similar to English:

• I wanted to go
• I wanted to buy
• I wanted to get

In Hebrew:

• רציתי ללכת = I wanted to go
• רציתי לקנות = I wanted to buy
• רציתי להשיג = I wanted to get / obtain

The ל־ at the start of להשיג is the normal marker of the infinitive in Hebrew.

להשיג usually means to obtain, to get, to secure, or sometimes to achieve.

In this sentence, it means something like:

• to get tickets
• to obtain tickets
• to manage to get tickets

It does not necessarily focus on buying them. If you wanted to emphasize buying, Hebrew might use לקנות.

So the nuance is:

• להשיג כרטיסים = get/secure tickets
• לקנות כרטיסים = buy tickets

Here, להשיג sounds natural because the speaker is talking about trying to get tickets, and then discovering none were left.

Because the sentence means tickets in a general, indefinite sense, not the tickets.

• כרטיסים = tickets
• הכרטיסים = the tickets

So:

• רציתי להשיג כרטיסים להופעה = I wanted to get tickets for the show
• רציתי להשיג את הכרטיסים להופעה would mean something more specific, like I wanted to get the tickets for the show

In English, we also often say simply get tickets, not get the tickets, unless we mean specific ones already known in the conversation.

Here להופעה means something like for the show or to the show, depending on how naturally you would translate it into English.

• הופעה = show / performance / concert
• ל־ before it can express destination, relation, or purpose depending on context

So:

• כרטיסים להופעה = tickets for the show / tickets to the show

This is very common in Hebrew. You will often see ל־ where English uses for or to.

Examples:

• כרטיס לסרט = a ticket for/to a movie
• כרטיס להופעה = a ticket for/to a show
• הזמנה למסיבה = an invitation to a party

כבר לא means no longer, not anymore, or sometimes just already not, depending on what sounds natural in English.

In this sentence:

• אבל כבר לא נשארו = but there were none left anymore / more naturally, but there were no tickets left

A very useful thing to remember:

• כבר = already
• לא = not
• כבר לא = no longer / not anymore

Examples:

• אני כבר לא גר שם = I don’t live there anymore
• הוא כבר לא עובד פה = He doesn’t work here anymore

Here it gives the idea that by the time the speaker tried, the tickets were already gone.

Because it refers to כרטיסים (tickets), which is plural.

• נשאר = remained / was left (masculine singular)
• נשארה = remained / was left (feminine singular)
• נשארו = remained / were left (plural)

Since כרטיסים is plural, the verb is plural too:

• לא נשארו כרטיסים = no tickets were left / there were no tickets left

Even though כרטיסים is not repeated in the second clause, it is understood from the first clause, so the plural verb still matches it.

Because Hebrew often leaves out a word if it is already clear from context.

The full idea is:

• רציתי להשיג כרטיסים להופעה, אבל כבר לא נשארו כרטיסים.

But repeating כרטיסים would sound unnecessary here, just like in English we often say:

• I wanted to get tickets, but there were none left.

We do not need to repeat tickets because it is obvious what none refers to. Hebrew does something similar by simply saying לא נשארו (none were left / there were none left).

Very literally, it is something like:

• אבל = but
• כבר לא = no longer / already not
• נשארו = remained / were left

So the clause is roughly:

• but no longer remained
• or, more naturally in English, but none were left

This is a good example of how Hebrew and English organize ideas differently. Hebrew often uses a verb like נשאר (remain / be left) where English prefers there were no ... left.

הופעה is a general word for a performance or show. Depending on context, it can mean:

• a concert
• a live performance
• a comedy show
• a stage performance

So כרטיסים להופעה could be:

• tickets to a concert
• tickets to a performance
• tickets to a show

If the meaning shown to the learner is show, that is perfectly natural. In another context, concert might also be the best translation.

Yes, in some contexts Hebrew speakers might also say נגמרו (ran out / were sold out / were finished), but it changes the wording slightly.

Compare:

• לא נשארו כרטיסים = there were no tickets left
• הכרטיסים נגמרו = the tickets ran out / sold out

Both are natural, but לא נשארו focuses on the fact that none remained, while נגמרו focuses on the fact that the supply was exhausted.

So the original sentence is very natural, and it matches English well: but there were none left.