I've done research on bitcoin and I know what it is and how it works, kinda. I've even built a small block chain app.
What I don't understand, and I haven't been able to find the answer to, is if I own some bitcoin, how does that help me buy groceries at the market, or gas for my car? The market I go to doesn't accept bitcoin and neither do the gas stations. If I can't do that, how is bitcoin worth anything to me?
If you cannot find any business accepting Bitcoin in your area, you might want to start it, assuming it is legally accepted in your country. That would attract Bitcoin supporters in your locality and might be imitated by other businesses. Other than that, Bitcoin is actually more acceptable online. Business in the outside world are normally attached to the usual fiat-based payments. You might also be able to use Bitcoin in peer-to-peer transactions.
Also, how are people supposedly getting rich with bitcoin? I thought it was a currency, where we can buy things. Then I find that it's also a commodity where we can trade it.
The fact that a single bitcoin was approximately equal to a few cents when it first came out, but now is worth tens of thousands, is very troubling.
This currency is just like the rest of the fiat currencies whose value is rising and falling. Moreover, you can also trade fiat currencies just like Bitcoin. The huge difference is that Bitcoin's value is generally appreciating while fiat's value is depreciating. Thus, the very observable rise in Bitcoin's value over time.
That, to me, is not troubling at all. It is much much better than fiat's system.