You can start right now with the equipment you have on hand, Plus the content you create with added video can be repurposed several more times than an audio only version of your show. Continue to publish the MP3 file to your RSS feed and podcast directories, but now you can create multiple Instagram reels, TikTok and YouTube shorts with your full episode content.
When you use a platform like Riverside, you can even offer private live streams of your show to paid supporters, either through Patreon member full, or sending an audience link to your email survivor. While you can share an audio only clip with captions to social media, having simple video of you and your cohost in addition to those live captions can greatly increase your chances of virality.
So should you stick with your audio only podcast or add video two, we would encourage that it doesn't have to be in either or decision. One of the biggest challenges of moving to a video podcast is calling attention to something visually during the show, which would immediately make audio only listeners feel disconnected.