Here is a list of places to submit your podcast RSS feed to:-
Apple Podcasts read the Apple submission guidance here.
Google Podcasts – learn how to get listed.
Youtube – convert your podcast into a video and get access to everything youtube has to offer.
Audible – Part of the Amazon family of sites.
Podomatic – a strong directory with some great features such as rankings within a niche.
Listennotes – a nice directory.
Player FM – another good brand.