Writing? Could you explain my mistakes? Thanks.

Hello, my dear friend!
How are you doing? What's the weather like? It is unusually warm and even sunny today. Things are not bad for me.
Unfortunately, I am experiencing some problems at work, but I hope to solve them soon.
Today, we had a showrt working day and I came home very early.
Moreover, we will have a four-day long weekend which will last for four days.
Today, we are going to my sister's. I have to collect some documents from her flat.
I am going to have a dinner
Take care and keep in touch.