Advice on best way to structure pages

I have a very basic Wix website and need to add a series of content pages. The content types include podcasts, articles, infographics and videos. The site has a simple high level navigation bar but I have content that needs to be accessible from this navigation and possibly have it's own sub-navigation. I would like some advice on the best way to structure this in a way that makes it intuitive for the user. There are two objectives:

1) To make the content accessible by THEME, ideally from the main nav bar e.g.:
[content] section on main navigation bar > drop down by [theme] > each theme page linking to different individual content pages e.g. a podcast, theme series of different articles / podcasts. I would like to understand the best way to add (bookmark?) links at the top of the theme page to the various content further down the page.

I currently have the theme page template set up but am not sure if this is the best way to do it.

2) To have ALL The CONTENT visible or searchable (if possible) from one place on the site.

I am looking for support with this from someone who has experience of looking at information architecture and user experience with a solid understanding of the WIX platform and how best to do this.

I am not necessarily expecting a partner to actually carry out this work, but would like some advisory support initially.