Can you please elaborate on taking or giving interest in Islam, like under what conditions can we take or give loan on interest.

You can take loan from banks on interest without niyyat of interest .

Can a fasting person serve food to a person who is not fasting (intentionally or unintentionally) ?

yes

Sir ka masah karte wakht right hand ka extra paani waapas hatheli se kohni ki taraf aata hai to wuzu baatil hai? Aur bahot martaba ye hota hai k wuzu mukammil ho usse pehle hi chehra ya haath sukh jaate hai yaani halka sa bhi paani /gilahat nahi hoti, to is ka hal kya hai?

1- no problem
2- dobara wuzu karna hoga

1: does washing hands or face after wudu invalidate wudu??
2: helping a child in taharat invalidate wudu,, when najasa is on our hand???
3: during ghusl, is it compulsory/wajib to wipe aaza e ghusl with hand ((as in wuzu)) or just reaching water/washing is enough?

1- after the completion there is no harm in it.
2- only you need to do taharat of the hand wudhu is valid and in order
3-wiping is not must

Yeh kaha jaata hai ki Nahjul Balaghah ke khutbah numer 226 me " fulan fulan" se murad Umar hai.
Iss baat ka dawa Ibn Hadid ne apni Sharha me bhi kia hai ki Sayyed Razi ne khud " fulan fulan" ke lie footnote me likha hai " Umar".
Lekin aaj kal ki Nahjul Balaghah ki kitabon me Sayed Razi ki yeh footnote maujood nahi hai.
Toh iski wajah kya hai ki Umar ka naam chupaya gaya hai..
Aur Maula Ali ne Umar ki tareef kyu ki?

Mola ne Umar ki tareef nahi ki hai.

Can you kindly give me a dua for marriage

recitation of sura Taha with Hadees kisa .

Do you have a dua for to read for marriage ?

pray 2 rakaat namaz,, in both rakaat recite hamd and yaseen and after namaz recite this dua...allahumma aghneni behalaleka an haramik wa betaateka an masiyatik

ghusl e janabat ke liye maine tayyamum kiya.
kuch der baad wuzu jitna pani mila toh kya kare. wazu kare ya tayyamum?

taymmum for ghusal .

mujhe naye Ghar me daakhil hote waqt Kya padna chahiye
aur sab Islamic ehkaam naye Ghar ke liye

Quran + Hadees Kisa padhein.

We went to restaurant where the cook drinks alcohol .
1. If he touches the food without washing his hand then the food is najis?
2. Is it permissible to eat at that restaurant?
3. Is touching alcohol najis ?

1- yes. najis
2- if pak then can eat
3- yes

If some one is suffering from urinary tract infection and some liquid discharges or urine then is it obligatory to change the cloths and wash it for salat ?
And does that cloths transfers najasat ?

first confirm about that liquid . if that's urine then najis .

Aqeedah kise kehte hai?

aqeeda means faith of a momin .