Is some trading content OK or not? If not I'd look for Facebook groups maybe.

In the states you can reach out to your local AAII group and see what sites they use, too--some have email lists and there are some pretty epic presentations out there. Here's one I liked from my chapter, Petaluma:

https://www.youtube.com/watch?v=PEOjBcn3GKw

If some trading is OK, you might also take a look at Ed Seykota's Trading Tribe concept.

https://eseykota.com/TT/PHP_TT/home/index.php

If the resources themselves are important to you, Ritholtz shares a lot: www.ritholtz.com/blog

Tons more of those around: https://thecollegeinvestor.com/15601/the-best-investing-blog...

This is assuming you've already googled "investor community" and things like that.

I "know of" Finimize but I haven't tried it myself:

https://www.finimize.com/

Good luck in your search.

The platonic ideal once existed:

NewMogul https://web.archive.org/web/20090531210722/http://www.newmog...

Nickb's very own New Mogul: business, leadership, management and financial news.arc https://news.ycombinator.com/item?id=315793

Ask HN: Alternatives to New Mogul? https://news.ycombinator.com/item?id=913817

Tell HN: After suffering NewMogul withdrawal, I built another. Please stop by. https://news.ycombinator.com/item?id=915162

I think "Bogleheads Investing Advice". You can learn the investing philosophy from John Bogle, Bogleheads® Wiki [0]. Also, interacting with other people through its community [1].

[0] https://www.bogleheads.org/wiki/Bogleheads%C2%AE_investment_...

[1] https://www.bogleheads.org

For trading (not investing), there used to be: https://nuclearphynance.com/

But it seems mostly dead for some time now (although there is still a lot of good content there)