How does the usage of “had” and “have had” differ?

If you have had your belongings taken, are

you a miserable person?

Why is the word “have had” used for one time occurrences while

• the term “have” is used for such occurrences as well. Have or simple present is used for
• something more habitual And does that mean have and had

are interchangeable?

If you lost all your belongings they will always turn into a poor person. [=”People who had their belongings taken will turn into miserable people. Is

this assumption correct or do they imply different meanings?

Do people get sick from smoking cigarettes? What exactly is the actual name of a person?

Can you please explain if you can travel with kids?