Twenties is the best age to explore everything in you and in world, rarely after that age you get that much time and stamina to travel or to specially make a solo trip and here in your age if you are afraid of what might go wrong if you go solo for traveling let me tell you one thing if there is one thing that will go wrong there are tens of other awesome experience you well get there.
you might have no idea about new place, you might get scared for first time in between all the stranger faces but one thing for sure, it will not disappoint you.
So for the second solo trip of mine when I had no time I went to rishikesh. I was returning from haridwar to delhi in the morning, waiting for the bus, but for some reason couldn't get the bus for delhi so took another one and it dropped me to rishikesh. Though I had no plan and no intention to go I had to search for some places to see there and I got the complete one day travel itinerary for rishikesh that includes few places i visited to.
At first place I took an share auto for Triveni ghat from bus stand. It is a good, peaceful place to see if you're there.