Nepal is like a lighter version of india, where people are a bit calmer and it's less chaotic. being also mostly buddhist, it gets a different vibe as well. it's marked by it's contrast between the spirituality, happyness of the people and a remarkable stagnating economy - nevertheless very safe and confortable to travel to. kathmandu valley is home to many stupas, where buddhist relics are stored, and it's a place full of magic, beautiful sceneries, monkeys and pilgrims from all over the world.
I recommend mostly within Kathmandu going to Boudhanath and Swayambu Stupas, and spend some time in each place, to let the vibe sink in, and enjoy.
Another interesting spot is Phokara, around 300km away from Kathmandu, it's super clean, roads are well done and has a much calmer atmosphere. There is a large lake there which you can cross yourself by renting a small boat and hike up the hill to meet a japanese pagoda stupa. Prices overall in nepal are very affordable, and you can live very well for one month with less than 800$ - all foods and accommodations included. extra trekking trips, for example, to the annapurna base camp will add to your expenses. Be sure to be careful where to it, and a daily shot of vodka or kräuterlikeur will help you enormously!