All of the companies you've mentioned are "speculations." AMC is what's been called a "meme" stock. It was basically trumpeted on a Reddit user group called "wallstreetbets." At one point it was close to going bankrupt due to high debt levels and the pandemic, but wallstreetbets users bid the price up and it was able to recapitalize itself by issuing new stock. It was last profitable in the 2nd quarter of 2019 and has shown cumulative losses of more than $40.00 per share since then. I think I'll pass. Cannabis stocks were all the rage when several states and Canada legalized marijuana. I would place them in what is sometimes called the "fad" category. Fads come and go, and so do fad stocks. Another example of fad stocks would be companies in the 3d printer and solar industries. SNDL, to my knowledge, has never shown a profit. But here's the thing: sometimes when the fad fades good companies are thrown out with the bad. There might be opportunity here, but I would stick to quality companies, or perhaps consider a derivative investment (invest in the shovel company instead of the gold mine). The final company you mentioned, KRBP, was in danger of being delisted from NASDAQ for not filing its financials in a timely manner, never a good sign.
If you insist on investing in penny stocks, just understand that, thanks to thin markets, it's populated with charlatans who are looking to "pump and dump" particular stocks, hoping to drive up the price and then unload their positions to "greater fools" whom they hope are left holding the bag. So like investing in a ponzi scheme, timing is everything. Since successfully timing a stock trade is difficult if not impossible to do consistently compared to just holding a position, that's another reason I avoid them.
I'm not advising anyone to invest in particular companies, but these are examples of companies I currently own: Amgen (AMGN), Applied Materials (AMAT), Bristol-Myers Squibb (BMY), Cisco Systems (CSCO), Dick's Sporting Goods (DKS), eBay (EBAY), Intel (INTC), Qualcomm (QCOM) and Visa (V). All of them are profitable and can be acquired at reasonable prices. From the examples, you can see that I'm finding value in medical/drug stocks, retail, financial payments/services, and select, so-called "old tech" as opposed to some of the high-flying "new economy" technology companies in areas such as cloud computing.
Good luck, and happy speculating!