Lost a Chance A missed opportunity

This morning I looked at saw a foreigner walking down the street. I really wanted to greet / say hello to her but I was too shy. So I lost a chance to make a new foreign friend today. I am very sad.

Thanks for the anecdote.  I changed the title to something which sounds common in English to express your situation.  

Hi Mustofa,
At first, you "see" someone or something.  Then, if you are interested, you "look at" it/them.  

"Greet" is good but formal.  "Say hello" is informal and probably better in your situation.

We "make a new friend" or "make friends with someone".

Always "today" - never "this day".

Keep up the good work!  Kind regards, Michael