What a happy day!

Today is Sunday. I got up later than workdays. My husband had boiled milk tea and went out. After drinking the milk tea I cleaned my house and then invited my parents to my home for lunch. I love them very much. Every time I see them I'm always happy. I think parents are the greatest people for their children in the world. So I long for being a mother in the near future.
Oh, someone is knocking at the door. It must be my parents.
See you next time. What a happy day!

Here is how I would write something like this:

Today is Sunday, so I was able to wake up later than I normally do on workdays.  My husband and I had boiled milk tea in the morning, after which he went out and I began to clean the house.  I always enjoy being able to see my parents, so after the house was clean I invited them over to have lunch.  I think parents are the most important people to children, and I hope to become a mother in the near future.  Well, someone is knocking at the door, probably my parents!

See you next time!

Everything you say in English is correct, so you obviously have an understanding of the language and the vocabulary you are using.  I think what you need to focus on now is making your sentences flow better together and making them longer/more complex.  The way you wrote this is what we would call "choppy," because you only use sentences which are short and simple.  It's something that you will develop over time as you use English more and more :)

What a happy day!

Today is Sunday. I got up later than workdays. My husband had boiled milk tea and went out. After drinking the milk tea I cleaned my house and then invited my parents to my home for lunch. I love them very much. Every time I see them I'm always happy. I think parents are the greatest people for their children in the world. So I will be a mother in the near future.
Oh, someone is knocking at the door. It must be my parents.
See you next time. What a happy day!