Doress code make me annoy

I will go to the restaurant that requests doress code because my father reserved to talk with and celebrate me. Wait, I don't know doress code. What I should wear?

I researched and know some kinds of pattern. Maybe I should wear the dress that is business casual. But of cource I don't have appropriate clothes.

So I went to the clothing store, and bought a jaket and slacks. I don't like that wear because when I put on them, I feel I'm in business. I like casual wear like T-shirt and jeans. 

Um...I'm looking forward to going that stately restaurant, but it's melancholy to wear formal clothes. Do you understand my thought?