I barely slept last night. I'm still wide awake. I guess I was drank too much coffee. So, I spent the whole night talking with other people on Skype. I totally forgot I am going to have a trip with my sister. We planned on going to Hangzhou to spend our weekend. It takes 1 hour to go there from Shanghai by train. We had already bought the ticket so that we could get there by 2pm. It's 7:30am now. I should pick a bag for our trip even though it's only for two days.

Everything that Sumre did to correct your paragraph is correct. However, the very last sentence is technically right, but may not have the right choice of words.

"I should pick a bag for our trip even though it's only for two days."

This is technically a correct sentence. The grammar is right. However, by the way you wrote it, it seems to me that you want to "pack" a bag for your trip. Even though "pick" could be seen as correct, to "pack a bag" is a common phrase used in English for taking trips and most native speakers would hear "pick a bag" and think "pack a bag". Hope that helps a little :)