Sorry Frank, but you (like so many others on here) did not give us some vital information that we need to answer your question.
You would like an address to buy a 2nd hand bicycle but you didn't tell us where you are. And we are not psychic. So good luck finding your bike.
Try Goodwill or other thrift shops
Other people asked questions on similar topics, check out the answers they received:
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them