Hi can anyone check my grammar of using

1)더라고요 And 는데

Things I'm trying to say:

Last weekend I went to that restaurant,and the door was already closed(by the time I arrived) cause I've been late, It's too bad

上个周末我去了那家餐厅，因为迟了所以门关上了，真是太可惜了

지난주말에 그 식당에 갔는데 늦어서 문이 닫았더라고요 너무 아쉬웠어요

I might be making a lot of mistakes in just one sentence,thanks for point out in advanced 😊

Question

Hi can anyone check my grammar of using

1)더라고요 And 는데

Things I'm trying to say:

Last weekend I went to that restaurant,and the door was already closed(by the time I arrived) cause I've been late, It's too bad

上个周末我去了那家餐厅，因为迟了所以门关上了，真是太可惜了

지난주말에 그 식당에 갔는데 늦어서 문이 닫았더라고요 너무 아쉬웠어요

I might be making a lot of mistakes in just one sentence,thanks for point out in advanced 😊

Answer

지난주말에 그 식당에 갔는데 늦어서 문*이 닫았더라고요 너무 아쉬웠어요

That is very good.
The only issue I see is 이 in 문이 닫았더라고 (aside from missing a period at the end of the sentence). Your use of -는데 and -더라고요 are perfectly natural.

We say 문을 닫았다 (1. (I) closed the door. 2. A business closed (at the end of the day or permanently)), or 문이 닫혔다 (the door got closed (by the wind, etc)).

For a business closing after its hours. (가게가, 음식점이) 문을 닫았다 is more common, even though 문이 닫혔다 might also be used.

Answer

门关上了just means the door is closed. 
You may say关门了to express that the restaurant is closed.

Answer

Oh I see what are you trying to say...
Do you mean I have to modify the sentence to something like this 
지난주말에 그 식당에 갔는데 늦어서 문이 닫았더라고요, 너무 아쉬웠어요.

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