Front desk/security gave info about me , my personal information such as who is paying my rental and front desk/security also gave the stranger my unit number I live in which became a harassment situation

Is this a legal matter for suit?

What country is this?
It does sound like you have a case, but you need to be able to document all that happened, and you need to be able to prove monetary loss. You can try to sue for pain and suffering, but most small claims courts won't accept that kind of suit. So that bumps this civil case up to regular civil court, and you need a lawyer, although it's not required by law.
Did the harassment require police involvement? Is it ongoing?
The first thing you should do is state all that happened in writing to the owner of the building or the management company, with the promise that a lawyer will be contacted if you don't have a satisfactory resolution by a certain date.
Keep your statement short, with dates and events. Do not elaborate how you felt or what you thought except in one sentence at the beginning or end. Get the full name of the person on the desk and have copies of any pertinent papers.

Any question about law needs your general locale as laws vary by area.

The problem here is there may not be any laws guaranteeing your information.

I would, definitely, consult an attorney to see what might be your next course of action.

Who was this person and why were they looking for info about you? What did they tell the building to give them the info?

I am in Hawaii.
I have all the information documented but need help putting my letter together. I am looking for an attorney, would you know what kind of attorney I should seek?
I really do not have a monetary loss at this time, for it hasn't gone beyond what I stopped it at. However, the security did tell the stranger that I am married and my husband pays my rent and I have a boyfriend. This here I feel is not something that should be revealed to anyone, its personal information.
Thank you for your response. I do need info on what kind of attorney I am too seek

Any question about law needs your general locale as laws vary by area.

The problem here is there may not be any laws guaranteeing your information.

I would, definitely, consult an attorney to see what might be your next course of action.

Who was this person and why were they looking for info about you? What did they tell the building to give them the info?

Thank you, yes, I am looking into my suit if it has any grounds for me to pursue.
The stranger asking and wanting to reach me is a guy I bought a dog from.
I gave him a down payment of 100 and $200 balance.
He is deperate for his monies and started harassing me for payment, which he was out of line due to the dog was not his to sell.
I called the police the day he came to my place with his pit bull and two other people. The police reached his father and got the guy to back off for now.
Stranger is the person who told me that the front desk has no problems sharing all my information with him.

If you bought something from him, and owed him money, yes he actually can look for you, and try to recover his money.

It will be a matter for court, if you owe him money, Do you have the dog ? Have you paid for it, or still owe the 200.

But he is free to come to your apartment and ask for your information.

In most cases, there is no law protecting you from this being given out

I don't see any law that protects your information. However, there is an ethical issue here.

I would write a letter to the landlord advising him that the landlord's employees revealed information that should have remained private and asking the landlord to issue instructions about doing so to their employees.

You don't need a specialist lawyer.
You may pay a lot in fees, however, for little or no gain.
The question of who has the dog is important. You found out that it didn't belong to the man who sold it to you, so you won't pay the $200 due - fine, but you can't keep the dog, and you have to prove who owns it. You need to find that person and negotiate. You can't make that person take the loss of the deposit. That's your loss, and between you and the one who sold it to you.

How do you know this info was given to a stranger? " However, the security did tell the stranger that I am married and my husband pays my rent and I have a boyfriend. This here I feel is not something that should be revealed to anyone, its personal information."

How does security know you have a husband and a boyfriend? It doesn't sound like any secret knowledge was shared, more like this is common knowledge.

What is the building's privacy policy? I'm an investigator - many buildings have tenant lists posted, names on mailboxes.

And, yes, if you owed someone money they can track you down.

How were you harmed by the info being given to this person?

I don't quite understand the situation - you have a husband and a boyfriend but went to your father about this situation?