found zero items with a valid enclosure tag

Your feed both in the iTunes Store and when subscribing now shows numerous episodes so you have evidently corrected the problem. There is no further action you need to take - you cannot re-submit the podcast (or validate it in Podcasts Connect once it's up and running) and there is in any case no need to. When you want to add an episode just add it to the feed in the usual way. It will appear in the Store after a delay of (usually) up to two days, though subscribers will see it pretty well immediately.

I still don't see any episodes.

There is no episode in your feed at all, only the header section. Looking at your podcast in Apple Podcasts 'Browse' there are numerous episodes, but on subscribing there are none. So evidently you've managed to delete them. You need to restore at least one episode as soon as possible or your podcast may be removed from Apple Podcasts.