You can select a future publish date or backdate your episode to make it look like it was published in the past! Kevin will walk you through how to do that here:
Audio file: You can upload nearly any file type to Buzzsprout, but you’ll have the best results with a Wav file or a high-quality MP3 file. Buzzsprout can automatically make your audio sound better by turning on Magic Mastering. This is an extra fee but it sounds great and cuts out a ton of editing for you!
Proofread: Of course you can always edit the episode details, but some people will download your new episode within minutes of you clicking publish. You’ll want to check for any spelling errors before publishing.