jeomsimeneun gimbabirang tteokbokkireul meokgo, jeonyeogeneun mandurang guksureul meogeosseo.

에는 is made of 에 + 는.

• 에 marks a time expression, similar to at / in / on
• 는 is the topic marker, and here it often adds a slight sense of contrast

So:

• 점심에는 = at lunch / as for lunch
• 저녁에는 = at dinner / as for dinner

Using 는 helps set up a contrast between the two times:

• for lunch, I ate X
• for dinner, I ate Y

Without 는, the sentence would still be understandable, but 에는 makes the comparison between lunch and dinner feel clearer.

In this sentence, 에 marks when something happened.

So:

• 점심에 = at lunchtime
• 저녁에 = in the evening / at dinnertime

Korean often uses 에 with times to show when an action takes place.
Then when 는 is added, it becomes 에는, which gives that extra topic/contrast feeling.

이랑 means and when it connects nouns in casual speech.

So:

• 김밥이랑 떡볶이 = gimbap and tteokbokki
• 만두랑 국수 = dumplings and noodles

It is a very common spoken form. Other ways to say and between nouns are:

• 하고 — also common and conversational
• 와/과 — a bit more neutral or formal in comparison

So these are all possible:

• 김밥이랑 떡볶이
• 김밥하고 떡볶이
• 김밥과 떡볶이 / 김밥와 떡볶이 is wrong; it should be 김밥과 because 김밥 ends in a consonant

In this sentence, 이랑 fits well because the ending 먹었어 is also casual.

In Korean, when two nouns are joined with 이랑/하고/와/과, the object marker is often attached only to the last noun in the list.

So:

• 김밥이랑 떡볶이를 먹고
• 만두랑 국수를 먹었어

This is completely normal. The whole phrase functions as the object, and the particle appears at the end of that noun phrase.

You could think of it like:

• [김밥이랑 떡볶이]를 먹고
• [만두랑 국수]를 먹었어

But in actual Korean, the 를/을 is attached directly to the final noun.

먹고 uses the connector -고, which means and, and then, or simply links actions together.

The first clause:

• 점심에는 김밥이랑 떡볶이를 먹고

means something like:

• I ate gimbap and tteokbokki for lunch, and...

Then the final clause ends with:

• 저녁에는 만두랑 국수를 먹었어
• I ate dumplings and noodles for dinner.

In Korean, when clauses are linked like this, the tense is often shown only on the final verb, especially when both actions are in the same tense. So even though the first verb is just 먹고, the whole sentence is understood as past because the final verb is 먹었어.

Not by itself. 먹고 is just the verb stem plus -고, so it is a connecting form.

However, in a sentence like this, the tense is usually determined by the final verb:

• final verb: 먹었어 = past tense

So the earlier action is also understood as past:

• lunch: ate gimbap and tteokbokki
• dinner: ate dumplings and noodles

If you wanted to mark past tense more explicitly in both clauses, Korean sometimes allows forms like 먹었고, but in ordinary sentences like this, 먹고 ... 먹었어 is very natural.

먹었어 is the casual/informal past form of 먹다.

Levels you might compare:

• 먹었어 — casual, used with friends, close family, people younger than you, etc.
• 먹었어요 — polite everyday speech
• 먹었습니다 — formal, more official or stiff

So this sentence sounds like relaxed spoken Korean.

If you wanted to say the same thing politely, you could say:

• 점심에는 김밥이랑 떡볶이를 먹고, 저녁에는 만두랑 국수를 먹었어요.

Yes. In speech and informal writing, 에는 is often contracted to 엔.

So you may also see:

• 점심엔 김밥이랑 떡볶이를 먹고, 저녁엔 만두랑 국수를 먹었어.

This means the same thing.
The full form 에는 and the shortened form 엔 are both very common.

Korean often leaves out the subject when it is already clear from context.

In English, you usually need to say I ate...
In Korean, if everyone already knows who is being talked about, you can simply say:

• 점심에는 ... 먹고, 저녁에는 ... 먹었어.

The subject I is understood from context.

If you wanted to include it, you could say:

• 나는 점심에는 김밥이랑 떡볶이를 먹고, 저녁에는 만두랑 국수를 먹었어.

But very often, that would sound unnecessary unless you are emphasizing I.

Yes, usually it suggests a natural sequence:

• for lunch, ate gimbap and tteokbokki
• for dinner, ate dumplings and noodles

Because lunch happens before dinner anyway, the sequence is clear.

That said, -고 is a general connector and does not always strongly emphasize after that in the way -아서/어서 or then might in English. Here it mainly links the two clauses smoothly, and the time words 점심에는 and 저녁에는 make the order obvious.

Yes. Common alternatives are:

• 하고
• 와/과

So you could say:

• 점심에는 김밥하고 떡볶이를 먹고, 저녁에는 만두하고 국수를 먹었어.
• 점심에는 김밥과 떡볶이를 먹고, 저녁에는 만두와 국수를 먹었어.

The differences are mostly about style:

• 이랑, 하고 = conversational, natural in speech
• 와/과 = a bit more formal or written-sounding

Because the sentence ends with casual 먹었어, 이랑 matches the tone well.