Hongkong is an amazing city, i can't wait to going there.

Hong Kong is an amazing city and I can’t wait to go there.

I booked the tickets which will fly in April 18th, and back in 22th.

My tickets are booked and I will be flying out on the 18th of April and be back on the 22nd.

My friend Trista will come with me, she lives in Xiamen city. I am in Hangzhou.

My friend Trista will join me on the flight there. She lives in Xiamen city and I in Hangzhou.

(Alternate idea: My friend Trista lives in Xiamen city and will fly via Hangzhou, where I live, to accompany me on the flight there.)

We will meet selly in Hongkong who will go working in Australia. So we decided that meet her early before she leaving.

We planned our schedule so we get to meet Selly before she has to travel to Australia for work.

As we all know, Easter day will be coming soon in Hongkong, that must have lots of fun, such as finding Easter eggs and other interesting things.

We’re going to have lots of fun on Easter day in Hong Kong. There are many interesting things to do apart from finding Easter eggs. (You can add some examples here)

Selly will be our guide, she recommended lamma island, Saigon and Taiping Mountain.

Selly will be our guide in Hong Kong and she recommended that we visit Lamma island, Saigon and Taiping mountain.

I have read some tourism strategy, found much places are beautiful and fancy.

I have read about some beautiful and fancy places in a Hong Kong tourism brochure.

(Fancy is not a great adjective to describe tourist attractions. Consider using some words like - charming, cosmopolitan, exciting, lively, picturesque, magnificent, incredible, magical, etc.)

Hope this time, we can enjoy our trip.

I hope that this time we can enjoy our trip.
(You can add some context here. e.g. Did a previous vacation not go as planned?)