[Grammar] Check The punctuation plz

[Alhan]

Hi there,
I have 2 correct the punctuation mistakes in the following paragraph. The mitakes that I am facing trouble with are related 2 grammar. I can tell that commas are needed here but can anyone plz explain 2 me why they r needed???????????? Plzzzzzzzz reply as soon as possible coz i have 2 submit it by Wedensday

kindly check the punctuation of the whole paragraph and let me know if there are mistakes. HOpe 2 here from u soooooooon

here's the paragraph:

A Picnic

When we arrived at the picnic spot, we got out of the car and unpacked the food from the boot. Mom had made some cookies, sandwiches and cakes which were delicious. After we ate, we played a game of football but my team lost. Then, we went home.

[Soup]

Introductory elemets and subordinate clauses are usually off-set with a comma if they begin a sentence:

When we arrived at the picnic spot, we got out of the car and unpacked the food from the boot.

After we ate, we played a game of football but my team lost.

Then, we went home. <colloquial English>

Note, does which need a comma?

[Alhan]

thanx alot for replying. I do appreciate ur help