1. go out
   Intransitive
   Meaning: leave home and go to a social event
   Example: It’s Friday night.  Let’s go out!

   How many nights a week do you go out?

2. go out with someone
   Transitive, Inseparable
   Meaning: date
   Example: She has been going out with him since last year.

In the United States, it is normal for a couple to go out with one another for 2-3 years before getting married.  Is it the same in your native country?