Past simple, past continuous and past perfect

[fuadha]

Please if there is any mistake in the use of the Past simple, past continuous and past perfect; tell me why to choose another tense:
Zeina and Rana were born and went school in Aleppo, but they hadn't met until they were at university. 'I had just come back from a two year trip abroad and I hadn't known anybody', says Zeina. 'Rana worked in the library then, and I saw her every day. I liked her straightaway'. Zeina didn't feel the same first. 'I was unpacking some books when I Iooked up and saw this girl. She was wearing an awful bright green jacket. She looked a bit sad and lonely and I felt quite sorry for her. We talked and she told me she had just returned from a trip abroad and didn't know anyone. Anyway, I offered to introduce her to my friends and came to like her more and more. Two years later we have become best friends. We're inseparable'.

[bhaisahab]

Please if there is any mistake in the use of the Past simple, past continuous and past perfect; tell me why to choose another tense:
Zeina and Rana were born and went school in Aleppo, but they hadn't met until they were at university. 'I had just come back from a two year trip abroad and I didn't know anybody', says Zeina. 'Rana worked in the library then, and I saw her every day. I liked her straightaway'. Zeina didn't feel the same at first. 'I was unpacking some books when I Iooked up and saw this girl. She was wearing an awful bright green jacket. She looked a bit sad and lonely and I felt quite sorry for her. We talked and she told me she had just returned from a trip abroad and didn't know anyone. Anyway, I offered to introduce her to my friends and came to like her more and more. Two years later we have become best friends. We're inseparable'.

Just one change.

[fuadha]

Just one change.

Thanks alot Mr. bhaisahab

[Dawood Usmani]

Please if there is any mistake in the use of the Past simple, past continuous and past perfect; tell me why to choose another tense:
Zeina and Rana were born and went school in Aleppo, but they hadn't met until they were at university. 'I had just come back from a two year trip abroad and I didn't know anybody', says Zeina. 'Rana worked in the library then, and I saw her every day. I liked her straightaway'. Zeina didn't feel the same first. 'I was unpacking some books when I Iooked up and saw this girl. She was wearing an awful bright green jacket. She looked a bit sad and lonely and I felt quite sorry for her. We talked and she told me she had just returned from a trip abroad and didn't know anyone. Anyway, I offered to introduce her to my friends and came to like her more and more. Two years later we became best friends. We're inseparable' [now].

[bhaisahab]

Hi Dawood,
It depends really, on what the OP wants to say, whether 'became' or 'have become' is correct.