How do you start a romantic relationship in your country?

Do you have a common way to start a romantic relationship in your country?

In our country, we say, "I like you. Could you please go out with me?"
In this case, "go out" doesn't mean just "date" but it includs dating as your boyfriend or your girlfriend. ( It is tsukiattekudasai in Japanese) Usually guys say it. We don't say"I like you" to your family and friends. We sometimes say it as a joke or something though.

How do you know you and someone are a couple in your country?
Have you ever misunderstood something about it?
Do you say "I love you"?