Content Is King
Look, chances are your idea is good! If it matters to you, and you are truly passionate about exploring it, then it's worth podcasting about. It doesn't matter whether you have 20 downloads, or 20,000 downloads of your episodes. You have to establish first why you are actually undertaking the project, and what you hope to get out of the experience.
Write a little list:
Think about the idea that you have.
The genre/niche of your podcast
Your "mission statement" for what you'd like to get out of the podcast
Have a look at other podcasts in your niche/genre and see how they've done it. What have you liked, disliked, and what will make your podcast different to others in the same niche?
Is this an idea that you want to keep doing for multiple episodes, even if no one is listening to begin with (because consistency builds a following)
If your show is going to include interviewing other people, listen to a few podcasts that do the interview style really well.
Don't get overly caught up in creating a big outline, at this stage take your time doing a bit of research. Listen to other podcasts, use the production schedule to map the topics out and get a feel for how you will be different to others.
RESOURCES MENTIONED:
Download the production schedule that I mention in this video to get yourself organised.
Tips to put your guests (and yourself at ease)
Interviewers with mad skillz:
The School of Greatness - Lewis Howes
On Purpose - Jay Shetty
Great mainly solo podcasts:
Work Life - Adam Grant
The Confidence Chronicles - Erika Cramer