You can get one from a lot of places, like nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm or #NostrPlebs, or even make your own if you have a domain name.
Discussion
Mine is: simplysarah@iris.to right?
Question, if a client goes down what do I do about that? Do I still have the simplysarah@iris.to?
You should still have your NIP-05, as long as the service provider you're using is still online.