IELTS General Writing task 1; Letter to John - making arrangements

Please suggest me some tips on this task 1 which I have wrote the below letter and give some marks out of 9 band. It will help me to correct my mistakes.

A family member is coming to stay with you. He/she will be arriving by train in the morning, but you won't be home until the evening.

Write a letter to your relative. In your letter:

explain arrangements you have made for them to have keys and get into the house
tell your relative how to get from the train station to your house
say when you will be home and suggest what you could do together that evening

Dear John,

I am writing to let you know that I will be not available on coming sunday in home due to my personal work. I hope you are arriving on the same day. I will be back in the evening. Once you arrived in the station one of my close friend Mr. Sam will pick you up and drop in the home and do not forget to get the flat key from him if he missed to give.

After you enter the house first relax yourself, take a fresh bath and have a breakfast. In the afternoon time sharp at 12.30 pm my house maid will come and she will cook the lunch for you. After the lunch if you feel bore go to first floor there is a computer in a small room and play some games in the computer.

Anyhow I will be sharp at 6.30 pm in the home. You keep yourself ready to go out we will go any shopping mall or a movie.

See you soon,

Best wishes,
Irfan

You are writing to a relative, a known party, and therefore you should show more intimacy in your writing. First express him that you are happy to receive him;

I am so glad that you decided to visit us and I am really looking forward to seeing you soon at our place.
Now tell him your inability to be at home as he arrives;
However, I may not be able to pick you up from the terminal as promised because I have been suddenly called up to work on that morning for an urgent matter. I would certainly be free during the evening session and I have some plans for us to enjoy that evening together.