Can you please help me understand how these questions are fromed for the other persons?

If the topic is already discussed, can you please point where?

Thank you.

Where am I from? -

Where are you from? - Nerelisin?

Where is he from?

Where are we from?

Where are you from? - Nerelisniz?

Where are they from?

Elena has provided the specific answer for you but let´s look at it from a different and wider angle.

Let x be any word such as good, fine, sick, young etc.

x-(y)im = I am x

x-sin = You are x

x = He/she/it is x

x-(y)iz = We are x

x-siniz = You are x

x-ler = They are x

Example x=iyi=fine

iyi-(y)im = I am fine

iyi-sin = You are fine

iyi = He/she/it is fine

iyi-(y)iz = We are fine

iyi-siniz = You are fine

iyi-ler = They are fine

Now when x is a question word you need to change the order in English but Turkish one doesn´t change:

x=kim

Kim-im = Who am I (lit. I am who)

Kim-sin = Who are you (lit. You are who)

Kim = Who is he/she/it (lit. He/she/it is who)

Kim-iz = Who are we (lit. We are who)

Kim-siniz = Who are you (lit. You are who)

Kim-ler = Who are they (lit. They are who)

For your question x=nereli=from where

Nereli-(y)im = From where am I (lit. I am from where)

Nereli-sin = From where are you (lit. You are from where)

Nereli = From where is he/she/it (lit. He/she/it is from where)

Nereli-(y)iz = From where are we (lit. We are from where)

Nereli-siniz = From where are you (lit. You are from where)

Nereli-ler = From where are they (lit. They are from where)

As an answer let x=İzmir´li=from İzmir

İzmir´li-(y)im = I am from İzmir

İzmir´li-sin = You are from İzmir

İzmir´li = He/she/it is from İzmir

İzmir´li-(y)iz = We are from İzmir

İzmir´li-siniz = You are from İzmir

İzmir´li-ler = They are from İzmir

Then, the suffix -li -lı always adds meaning of place? 

Thak you, Luis.

Not always. 

Ex:

sevgi-li  love-r

değer-li value -able

haraket-li act-ive

You see it gives many different meanings.

The main function of the suffix -lı, -li, -lu, -lü is to form nouns from nouns which are often used as adjective

Having the characteristic of; having the quality of;consisting of; partaking of..

Yedi başlı ejderha – seven-headed dragon

Tek taraflı görüş – one-sided view

Kan lekeli gömlek - blood-stained shirt

Alçak tavanlı oda - low-ceilinged room

Renkli manzara – colorful view

Sevinçliydi - she was joyful,

Ümitliyim – I am hopeful,  

Milky desserts – sütlü tatlılar

Şekerli içecekler - sugary drinks

Tozlu  raflar– dusty shelves

Çamurlu su – muddy water

Killi toprak- clayey soil

Also

A person who belongs to/is a supporter of a political party, a football clup, etc.. AKP´li, CHP´li, Fenerli, Cimbomlu, Beşiktaşlı ..

inhabitant of x; of x descent.. şehirli, kasabalı, köylü .. Ankaralı, İstanbullu .. Doğulu, Güneyli .. Karadenizli, Egeli ..

What they are trying to tell politely here is that the meaning of place doesn´t come from the suffix -li at all.

The meaning of place comes from the ´re´ part.

Ne (what) + re (place) + li (with) = nereli? (where from, belonging to where)

Bu (this) +  ra (place) + da (in/on/at) = burada (here)

Ne (what) + re (place) + de (in/on/at) = nerede (at) where?

Ne (what) + re (place) + y (buffer) + e (to) = nereye? (to) where?

Ne (what) + re (place) + den (from) = nereden (from) where?