This is the first time for my I am writing an English diary. (Or you can also say: "This is my first English diary.")

This afternoon, I went to the PC mall with my friends at about 1:00 pm

The weather is was so hot, but I didn't feel the heat. that hot feel. (You can also leave out "the weather" and just say "It was so hot outside" or "It was so hot" because it will be assumed you are talking about the weather or temperature outside. You can also say, "I didn't notice the heat")

Because I enjoy was feeling so happy on the way to the PC mall with my friends. (This was a very good sentence! *smile*. The sentences should be combined to say, "It was so hot outside, but I didn't notice the heat because I was feeling so happy on the way to the PC mall with my friends." It's very long sentence right? *smile*)

I would like to buy a laptop, but i don't have enough money. (You can say, "but I didn't have enough money" also depending on your meaning. Do you mean to say that you didn't have enough money with you when you went to the mall? Or do you mean you don't have enough money to buy it yet? I think you mean "I didn't have enough money to buy it.")

I should be have enough money next time to buy it.

At about 11:00 pm, I arrived to home. (Or you can say, "I arrived back home.")