Anyone's most fascinating subject is ... them!
If you are getting one-word answers, you may be talking to someone who is equally shy! Try a few different neutral conversation topics - music and films are always good, and once the other person starts to talk, let them roll with it, asking just enough to kep the conversation going.
Try not to feel nervous, it communicates with non-verbal signals, and makes another stranger feel nervious as well.
The art of conversation is being relaxed, and interested, in that order - not to b confused with trying to be 'interesting' - which can make you sound like a self-centered bore!
Good luck.