@j_brayden1
I am visiting India at the end of October for 2 weeks. Am I trying to squeeze too many places in?
Yes - too many. With just 14 days in hand, consider limiting yourself to just 5 places.
Am I visiting those cities in the right order?
Not really, but the first problem is you have too many.
I want to focus most of my attention around Rajasthan. ... the food ... sight-seeing, hiking, YOGA(!) and getting off the beaten track to explore on my own. One concern ... really focuses on cities, old forts and temples. Ideally I would spend a few days practising yoga and would consider other places and even retreats if this was possible.
So, you really need some discipline about why you are going to India. You want to focus on Rajasthan, but you don't want too many forts (Rajasthan is known for its forts). You want to hike, but you're not headed to the Himalaya. You want to go on a yoga retreat - but have no time allocation for one.
Now the other side of the coin is that you can do yoga just about anywhere in India - if your accommodation doesn't have a drop in class, they'll know where one is; And if you get out of town you can hike - even in Rajasthan.
http://rajasthantrekking.com/trekking_in_udaipur.htm
I also want to try at least one train journey, preferably with nice scenery to enjoy during the journey.
This isn't something to which I warm. The point of taking the train is to go to sleep and wake up in your destination. "Nice scenery" is in the eye of the beholder. I think mountains and forests are "nice" - endless scrub, not so interesting.
I plan on staying in hostels as I'm in my twenties and want to meet people of a similar age.
If you've travelled before, you won't find hostels in India they way you may have found them in other destinations. Fewer in number, and emerging in the market you might consider some of the 'chain' options.
https://www.oyorooms.com/
https://www.zostel.com/
http://thehostelcrowd.com/
http://www.moustachehostel.com/
https://www.gostops.com/
http://www.roadhousehostels.com/
https://www.backpackerpanda.com/
http://crashpad.in/
Darjeeling and got to view Mount Everest. That's certainly something I would enjoy but not sure how feasible it is.
It's feasible if you make the time. Darjeeling is a fair hike, however. Let's say you went from Varanasi - it's a 12-15 hour train journey to New Jalpaiguri (the nearest station) and then another 3 hours by road to Darjeeling. It isn't any faster to get away from. Seeing Mount Everest would be sheer chance. You are most likely to see the five peaks of Kanchenjunga; but you would need near-perfect weather conditions to see Everest from Tiger Hill - and then using a telescope.
For the sake on providing some commentary on your original plan:
22/10/2018 Monday Varanasi (Flight at 9pm) 23/10/2018 Tuesday Varanasi
One day in Varanasi is just pointless really. Whilst many will have a love/hate relationship with Varanasi (a bit like India itself); to my way of thinking Varanasi is really somewhere to be and soak up, not a handful of sights to visit.
24/10/2018 Wednesday Agra (Fly back to Delhi and drive to Agra)
And that won't work. Even if you took the earliest flight to DEL, you are almost no chance to make Agra before dark. If you do beat the sun, you'll have almost no time in Agra at all. If you want to fly, then fly all the way - check the Air India schedule for flights to Agra.
25/10/2018 Thursday Jaipur (Fatehpur Sikri)
You could visit FS if you took a car+driver between Agra and Jaipur.
27/10/2018 Saturday Jaipur (Rathambore NP)
How do propose to get to Ranthambore? You would need to leave at an unShiva hour to make the morning safari. Doing just one safari (either morning or afternoon) doesn't seem worth the effort of getting there. You really need your accommodation to book your safari tickets - which will be more expensive but infinitely easier. And you never mentioned wildlife as an interest. Is it?
28/10/2018 Sunday Jodhpur (Train)
Nah. There is one train daily between Sawai Madhopur (the station nearest Ranthambore) and Jodhpur. It leaves before 06:00 and arrives after 18:00. Day blown.
30/10/2018 Tuesday Udaipur (Drive and stop at Ranakpur)
If you are going to stop at Ranakpur, you may as well stop at Kumbhalgarh.
https://www.lonelyplanet.com/india/rajasthan/kumbhalgarh
02/11/2018 Friday Delhi (Fly to Delhi) 03/11/2018 Saturday Delhi (Flight at 9pm)
Unbearably inefficient - from wherever you fly, fly in to DEL to make your connection out. Do not leave the airport a second time.
Finally, I included Udaipur at the end of the trip as I've heard this is a beautiful place to relax.
Well, I am of the view one can relax anywhere. That's rather the point of yoga. Udaipur is a pretty spot, built on artificial lakes.
So, said with all the love in the world, back to the drawing board. Get clear for yourself why you have chosen India, and what sorts of experiences you want to have, and what sorts of things you want to see. There are no wrong answers, and this is not a test - but it should help you decide where you go with your limited time.
https://www.lonelyplanet.com/india/planning/india-is-known-for/a/nar/0476bc35-a51d-4d42-8d89-404be5d62570/356195