I am trying to create a survey using node.js+ejs and try to save data in cloudant DB but i am new with that so anyone knows how to do that ?
Your question is very open-ended; if you're not showing code, it's hard to give appropriate advice. Cloudant's official node library is very well documented. I'd suggest you start off with learning how you use that to store simple documents, and building from there onto storing your survey results.