Hello Varsha,
How lovely that you are thinking of visiting Dublin this autumn! I would love to point you in the right direction so you can make your dream trip a reality. :)
For an answer to all three of your questions, I recommend reaching out to the Irish Embassy in the country where your passport was issued, so in this case you can contact the Embassy in New Delhi via the
following page. They will gladly walk you through the requirements, as well as the sign up progress, and give you all of the information you need.
I would however be delighted to help you find the perfect
place to stay in Dublin (or other places on the island), as well as things to
see, do and experience. Is there anything in Dublin you absolutely wouldn't want to miss? :)