About 3 Weeks (solo) in India - First Trip

I was wondering if I could get some advice on what to go see/do in India for my first trip there (well first trip in 13 years when I was like 12). Some basic info:

-I'll have about 3 weeks there and am flying into Delhi.

-I probably will stay more North and Central (and include Goa). Though I'm open to ideas that include the South.

-I want the trip to be somewhere between a touristy and backpackers trip. Let's say a water down backpackers trip

-Assume money is not really a constraint

Any suggestions on things I should see/do. Where are places that backpackers typically go. Where can I go to meet other backpackers? Opportunities for some fun and adventure (whether off/on the beaten track). Sites I should definitely go see. Things I should experience (like a sunrise/sunset here, bathing there, etc.)

Thanks for your advice!

hi akchahal, and welcome to indiamike.

i see your post has gone unanswered for a bit and your trip is fast approaching. unfortunately, it's really hard for other members to answer such broad inquiries.

i suggest you thumb an india travel guide to see what areas or specific sites interest, or spend a few hours persuing the forums here. if you look at the itinerary threads, perhaps you can get a sense of how others have arranged three-week trips. then, you can post more focused questions, and likely get more replies.

good luck!