Walaykum asalam wa rahmatullahi wa barakathu! :)
Instead of answering all of your questions, I’m going to link you to a great PDF/book solely about dua, called Dua: Weapon of a Believer. It’s 237 pages long but you can check out the index to find answers to your questions and more insha’Allah.
Forgive us for answering this so so late and let us know if you need more help.
Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah (PBUH) said, “When a Muslim, or a believer, washes his face (in the course of Wudu’), every sin which he committed with his eyes, will be washed away from his face with water, or with the last drop of water; when he washes his hands, every sin which is committed by his hands will be effaced from his hands with the water, or with the last drop of water; and when he washes his feet, every sin his feet committed will be washed away with the water, or with the last drop of water; until he finally emerges cleansed of all his sins.” [Muslim].
Kashmiris perform ablution near a fountain at the landmark Jamia Masjid during Ramadan in Srinagar.