You can start with either Rajasthan or Himachal Pradesh. You will come across a number of domestic as well as foreign solo as well as group travellers in both the above places and also there are plenty of hostels to stay, meet and mingle with like minded travellers.
If someone really interested for its 1st solo trip then there are many places in India and in the state Odisha too. Places like Puri, Konark and other places one can visit. During the visit one can search many hotels in Bhubaneswar The HHI Bhubaneswar is one of them. Which provides better facilities at a very affordable price.