Amateur investor curious about the returns from learning investment strategy

So, just to kick off, let me get the obvious out of the way: I know knowledge is power so there isn't any drawback to knowing more.

Background: I'm a full time employee who took 5 figures of savings and was fortunate to take them to 6 figures during covid. I mostly did this by only researching the absolute basics of investing (different types of investments, terminology, dollar cost averaging, risk reward stuff and downside protection), coupled with diligence in waking up early to read news and trade, gut feelings and intuition, and a good dose of luck. I'm mostly a long term trader atm with a smaller portion of my portfolio in speculation stocks.

I also understand the phrase "every investor is a genius after a crash" or to that point. Since the 2020-2021 crazy runups I've sold most of my risky stuff and parked 90% of my port in blue chips, dividends, and the like. My goal is to generate enough passive income to free up time.

Now to the meat: The current market doesn't seem to make a lot of sense to me. Stocks go down on good news, up on bad news, companies with giga low EPS seem to have massively bloated market caps, and generally, outside of the general turmoil of global and Trump politics, stocks seem to behave in a way i often can't fully understand. A lot of finance jargon is dropped in forums and news stories that i don't always fully understand. I'd like to have more ammo to bring to the table for stocks in general, but especially mid cap speculations.

So my questions are

1 - is it generally worth my time to take a course or read lots on advanced investment strategies as a blue collar? Or should i simply keep it simple?

2 - if it is worth it, what are good and affordable books, resources, or online courses i could take?

3 - is the stock market just a different beast today than it was 30 years ago, IE has AI, online retail investors, dark pools and other tomfoolery just made speculation stocks too crazy to understand?

Thanks in advance