В прошлом году моя подруга стала офисным менеджером и получила первую стипендию.

«В прошлом году» is the normal, idiomatic way to say “last year” in Russian.

Grammatically:

• в
  • предложный падеж (prepositional case) is used here to mean “in (a period of time)”:
    • в этом году – this year
    • в прошлом году – last year
    • в следующем году – next year

So you get:

• прошлый год (nom./acc. “last year” as a noun phrase)
• в прошлом году (“in last year” → last year as an adverbial time expression)

«В прошлый год» is technically possible but extremely rare and stylistically marked; learners should treat «в прошлом году» as the only natural option for “last year” here.

Both «прошлом» and «году» are in the prepositional case, singular:

• прошлый → в прошлом (prepositional masc./neuter singular adjective)
• год → в году (prepositional singular of год)

The prepositional is required because of:

• the preposition в (in this time expression)
• and the meaning “in (a year)”

Note that «год» has an irregular prepositional form: в годе exists but is very rare; with time it’s essentially always в году.

Because «подруга» is a feminine noun, and the possessive pronoun must agree in gender:

• мой друг – my (male) friend
• моя подруга – my (female) friend

So:

• мой is used with masculine nouns.
• моя is used with feminine nouns.

Using «мой подруга» would be grammatically wrong.

In Russian, past tense verbs agree with the subject in gender and number.

The subject is «моя подруга», which is feminine singular, so the verbs take the feminine singular past ending -ла:

• masculine: стал, получил
• feminine: стала, получила
• neuter: стало, получило
• plural: стали, получили

So we must say:

• моя подруга стала … и получила …

Because the verb «стать» (“to become”) normally takes its complement in the instrumental case, not the nominative:

• стать кем? чем? – to become who? what? (instrumental)

So:

• офисный менеджер – office manager (nominative)
• офисным менеджером – (by) an office manager (instrumental), used after стала

Other examples:

• Он стал врачом. – He became a doctor.
• Она стала директором. – She became a director.

So «стала офисным менеджером» is the correct grammar.

«Офисным менеджером» is instrumental singular:

• офисный → офисным (masc. sg. instrumental adjective ending -ым)
• менеджер → менеджером (masc. sg. instrumental noun ending -ом)

Instrumental is used here because of стала кем? – “became who?”

Pattern:

• хороший врач → хорошим врачом
• новый директор → новым директором
• офисный менеджер → офисным менеджером

You can say «она была офисным менеджером», but it means something slightly different:

• стала офисным менеджером – she became an office manager (focus on the change / the moment of becoming).
• была офисным менеджером – she was an office manager (focus on her state at some time in the past, not the moment she got that job).

In the original sentence, the idea is that last year something new happened: she got that position. That’s why «стала» is more appropriate.

• получить (perfective) → получила – one completed action: she got/received (once).
• получать (imperfective) → получала – repeated or ongoing action: she used to get / was getting.

In this context, we’re talking about:

• one specific event in the past (her first scholarship), so Russian uses the perfective:
  … и получила первую стипендию.

If you said «получала первую стипендию», it would sound like the process was ongoing, or repeated, which clashes with «первую» (the first, single one).

In Russian, when two verbs share the same subject, it’s very common to:

• mention the subject once,
• then just list the verbs joined by «и».

So:

• Моя подруга стала офисным менеджером и получила первую стипендию.

The subject «моя подруга» is understood for both стала and получила.

You can say «… и она получила…», and it’s not wrong, but in this short sentence it’s unnecessary and less smooth.

Literally:

• первая стипендия – the first scholarship/grant/stipend (nominative)
• первую стипендию – “(her) first scholarship” in accusative (direct object)

Forms:

• первая → первую (feminine sg. adjective: nom. → acc.)
• стипендия → стипендию (feminine sg. noun: nom. → acc.)

We use the accusative because she received what? – первую стипендию (direct object of получила).

«Стипендия» is not a normal salary. It is:

• money paid to students, graduate students, sometimes researchers or trainees, usually on a regular basis,
• as financial support or a merit-based award.

So it corresponds best to “scholarship”, “grant”, or “stipend” in English, depending on context.

It’s not used for a normal employee’s wage; that would be зарплата (salary, paycheck).

Yes. Russian word order is relatively flexible, especially for elements like time expressions. All of these are grammatically correct (though slightly different in emphasis):

• В прошлом году моя подруга стала офисным менеджером…
  Neutral, typical: sets the time first.

• Моя подруга в прошлом году стала офисным менеджером…
  Slightly more focus on my friend, then when it happened.

• Моя подруга стала в прошлом году офисным менеджером…
  Possible, but less common; sounds a bit more marked.

For learners, the original order is the safest and most natural:
В прошлом году моя подруга стала офисным менеджером и получила первую стипендию.

Yes, both are correct but slightly different:

• В прошлом году – last year (refers to the previous calendar year).
• Год назад – a year ago (exactly about 12 months before now, not necessarily the previous calendar year).

Examples:

• В прошлом году моя подруга стала офисным менеджером… – This happened at some point in the previous year.
• Год назад моя подруга стала офисным менеджером… – This happened about one year before today.

In everyday speech, they often overlap in meaning, and both sentences are fine.