Do I have to purchase the item if someone sends me an offer? And how long does the search remain active?

No, posting a Looking For listing does not obligate you to make a purchase. The goal is to allow sellers to make offers – and it's up to both parties to decide whether a transaction will take place.

By default, Looking For listings remain active for 180 days. After that, they are archived. You’ll receive a reminder before 30 days of expiration, and you’ll have the option to renew the post if needed.