it is good if it has some threat about teaching Hindi to foreigner.
Just greeting, or useful sentence that we can use in our daily life if we have Indian friends.

'Namaste' is a greeting you can use.

you can write hindi in roman script anyway...
it's good for you to learn as many languages as you can it helps you when you're stuck in the place you're visiting

mera naam .... hai.
my name is ....

aap ka naam kyaa hai?
what is your name?

aap kahan rehte hain?
where do you live?

phone number baat ki ji ye.
please tell me your phone number.

subh bhagyamani good luck

i dunno if those are correct but i just type whatever i could remember

Hindi is a version of northern indian language spoken in india side, while urdu is another version spoken in pakistan but it also exist in india side. If you write in arabic script then, urdu is quite useful but romanized hindi and urdu are easier compared to devanagri or arabic written language if you choose to quickly speak those languages.

Namaste is normal greeting in india, but salaam is quite common too. Other poetic version i guess is adaab which also means hi but i guess it's not used anymore today. try to watch few movies from india or pakistan with english translation and you'd grab some words. Those languages are quite interesting since they had separate development but quite similar. Hindi has Sanskrit words more while Urdu has more Persianized and Arabized words.

Hindi or Urdu could also be understood by Punjabis I believe. But Punjabi tends to be more like regional language with its own written language called Gurumukhi. My dad loves to watch Hindi movies and these movies had penetrated our state since 50's along with Middle East movies from Egypt and Syria but Mid East movies had ceased to be shown in TV while Hindi and Tamil movies still continues to be played especially during special occasions or days, lol

So, these are from movies script or titles and people here learned Hindi like this... lol

Ishq Love
Pyaar Ishq Aur Mohabbat Love, love and love (prem also means love in Hindi)
Pagaalpan Craziness
Dil Hai Tumhara This heart is yours
Mohabbatein Love story
Jaanam Samja Karo Dear, please understand
Mein Hoon Naa I am here
Dil Ka Rishta Heart relationsip
Kaho Naa Pyaar Hai Say that you love me
Kuch Kuch Hota Hai Something happened
Dushman Enemy
Dhadkan Heartbeat
Mann Soul
Mujhse Shadi Karogi Will you marry me?
Mujhse Dosti Karogi Will you be my friend?

better share movie lines, it would be easier to learn, ahahahaa...

Basic Numerals

You may use these when you perform pilgrimage in Mecca. Those people there doing business in Urdu, Malay, Turkish and Arabic.

1 Ek
2 Do
3 Teen
4 Char
5 Panch
6 Chey
7 Sat
8 Aat
9 No
10 Dass

Tum kaise ho / Aap kaise hain?
How are you?

Main achha hoon
I'm fine...
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Kya tum mujhe apna pen doge?
Can you lend me your pen?

Haan, zaroorya
Ya, Sure...
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Kya yeh ek kitab hai?
Is this a book?

Haan, yeh ek kitab hai
Yeah, it's a book..

I would recommend you to watch some Hindi TV series, they are from India.

Shree
Choti Bahu
Pavitra Rishta

I watched many Hindi TV series at Zee TV last time when I was in vacation.
But had forgotten many of their titles
Most of times I watched Tamil movies in Vellithirai Tv too and they are fun to be watched
You get entertainment, you also get language or at least new words and use it right away with your freinds