Nepalgal do not worry about transit visa for amsterdam, I actually had transit there at amsterdam a year back,from amsterdam to delhi and from delhi to ktm, the same route to get back (note- if u are flyin to kathmandu by Nepal airlines*RA* then be ready to expect hugeeeeeeeeee delay at delhi kinani RA sadhai late huncha ani time ma kahile uudhdaina). I think you got ur ticket from makemytrip.com KLM/Northwest  airlines. tyesto transit visa kei pardaina I had long transit there for like 8 hours or so(i have heard many countries require a visa if stayed more than 12 or 14 hours ,check that with ur travel agency but less than 12 amsterdam wont require visa, unless u want to go out of the airport.. Enjoy the airport, because it is relatively much smaller than other european countries airport but seems cleaner hehe. sleeping wont be a problem because there is comfort seat where u can sleep. so relax, dont worry and begin shopping, enjoy ur trip back home **be safe in Nepal**.
HOPE this solves ur question.

I would like to ask few more questions so u wont have luggage problem which wont happen likely but can happen sometimes, I have seen it there,"i was lucky it didnt happen to me, but the person flyin with me wasnt that lucky".
Ur flight is directly connected to KTM from US? or did u buy the ticket separately to kathmandu from delhi? coz if u got the ticket separately den here is the suggestion- everyone will b told to follow the stairs down and dont go beyond the immigration line,but I will suggest u to check out and re-check in if u have enough time for ur another flight(make sure u have the ticket to kathmandu so u can enter the airport again.,that will ensure u that ur bags are safe and arent misplaced..and will have peace of mind, got the picture? it wont b much hassle as it sounds like hehe, if u are confused regarding the suggestions i made, feel free to ask me again.